What is a normal PDO?

Leave a reply

The ever present challenge in football analytics is separating luck from skill. In a low scoring sport such as football, there will always be teams that fly high simply due to a spell of good fortune, and teams that find themselves in a hole they did not really deserve to be in on the basis of their displayed skill level. This is particularly true in Cup competitions, which are notorious for their surprise results, but even a common double round robin format that is used in most leagues around the world is too short to consistently identify the truly best team.

The challenge is to tell teams apart according to their true skill level, and not to get sucked into the group of people jumping on the bandwagon of teams that simply owe their ‘great performance’ to a spell of good fortune.
A very helpful tool to separate luck from skill is the concept of PDO. This is a very simple metric that originates from the low-scoring sport of ice hockey but slowly finds its way into football at present.
For a detailed description of the concept and the logic behind PDO, please read the introductory post on PDO.
In short, PDO is computed from a team’s saves percentage and the same team’s shot percentage. Start with the total number of goals conceded and scored, collect the total number of shots conceded and created and you’re all set. Simply add the team’s saves percentage and shot percentage together and to get rid of the decimals, multiply by 1000. Since one team’s goals are always another team’s failed saves, the league wide overall PDO will always be 1000.

One of the most fascinating things of PDO is that is seems to revert back towards the mean of 1000 for all teams. Although intuition will tell you that better players will finish a higher rate of chances presented, the raw numbers seem to tell that better teams don’t separate themselves from weaker teams by consistently obtaining higher shots and saves percentages. Much of this bears down to this influential post by the fantastic James Grayson, who analyzed ten seasons worth of EPL data to prove that PDO indeed moves ever closer to 1000 as the season progresses.

But the question for this post is, what is a normal level for PDO. Does it continue to regress towards 1000 as matches keep being added, or is there a certain bandwidth of normal PDO levels?

In this graph, Infostrada Sports data has been used to assess PDO levels since the start of the 2010/11 Eredivisie season. So, the horizontal axis contains two and a half seasons of Eredivisie matches with individual match rounds simply numbered from 1 to 86. The vertical axis presents the PDO levels and the lines represent the four different quartiles, with Q1 being the top-25% and Q4 the bottom-25% teams in terms of PDO levels. In order to smooth the curves, the single highest and lowest PDO teams have been left out, which also helps to create four nice groups of four teams out of all 18 Eredivisie teams.

Essentially, this is a repeat of James’ work on the concept that PDO regresses towards the mean of 1000, but the graph is extended beyond the single season level of 34 matches. And as you can easily see, the regression towards the mean seems to stop around the 40 matches mark.

From there on, a zone of PDO from 980 to 1020 nicely captures the average PDO and it no longer narrows down further. This probably means that superior teams separate themselves from inferior teams in terms of PDO, but only within this range. Teams that find themselves in a nice league position with PDO levels above 1020 will revert back over time, but top teams with PDO levels of 1020 may not necessarily follow that path as this PDO of 1020 may well be that team’s baseline. Also, inferior teams with PDO levels around 980 may not safely assume that fate will revert their lower league standing over time, as 980 may well be their baseline PDO level.

We can produce the same graph for both components of PDO: saves percentage and shots percentage.

These graphs learn us that the zone of saves percentage ranges from 87% to 89% and that the zone of shots percentage ranges from 10.5% to 14%. Teams with performances outside these zones have historically been unable to sustain that kind of level and will be expected to regress back to these zones within one season’s time.

In the end

PDO is a powerful concept to separate lucky teams from unlucky teams. Due to the low scoring nature of the sports, luck is an essential component of achieving a good league table position, but it is generally neglected when evaluating the performances of football teams. A high PDO refers to teams that stand on a high they did not earn, while low PDO teams find themselves in a hole they did not deserve.
The original thinking involved the notion that PDO will revert back towards 1000 over time, and while this is certainly true for values outside the 980 to 1020 zone, it seems better to rephrase and say that PDO will revert back to the 980 to 1020 zone, rather than towards 1000 for all teams.

Separating home and away strength

2 Replies

Would you rather play Ajax at home or NAC away?

Obviously, Ajax is a lot stronger than NAC, but playing at home is preferable to playing away from home… Difficult choice I would say, and luckily, only a hypothetical one, since managers control a lot, but not which team they play at which venue in competitive matches!

Just like the concept of Relative Shots Rate (RSR) can be used to separate offensive and defensive strength, it can also be used to separate home and away strength. RSR is calculated using a team’s performance relative to the performance of other teams that played the same fixture, and not simply by counting shots alone, like the Total Shots Rate, or TSR, would do. This means that a correction for the strength of opposition and the venue of the fixture is implemented in the measurement of RSR.

The diagram below depicts team on the basis of their RSR in home (vertical axis) and away (horizontal axis) matches. The fat red line is the trend line that separates teams that are stronger away from home (below the line) from teams that are stronger at home (above the line).

Relative Shot RatesEredivisie 2012/13Match Day 1 - 16

Several obvious things can be noted, before we will go on to discuss most of the teams.

First, as expected, home teams create more shots. The average number of shots for home teams in the 2012/13 Eredivisie so far has been 14.33, while away teams have created an average of 11.11 shots. The average home RSR is therefore 14.33 / (14.33 + 11.11) = 0.563, while the average away RSR is 0.437.

Second, and also not a surprise, teams that have a higher home RSR also tend to have a higher away RSR. In fact, there a no teams with a higher away RSR than home RSR, indicating that there are no teams that are truly stronger away from home than at home. There may be quite some teams that have picked up most points away from home this early in the season (PEC Zwolle, Groningen, ADO, N.E.C., Utrecht and Vitesse) , but no teams consistently produce more points on the road than at home.

From the graph it is quite clear that PSV separates itself from the rest of the title contenders, both at home and on the road. They are the best in both RSR’s, and by a distance. The three of Ajax, Feyenoord and Twente are quite close together and are quite close to the trend line, indicating a good balance between home and away strength.

Heracles, Utrecht and RKC are 5th, 6th and 7th in overall RSR, but Utrecht does so in a different style than Heracles and RKC. Utrecht’s home performance is one of the most disappointing ones in the league (with N.E.C. and PEC Zwolle who are also way below the trend line), while away from home Utrecht is right up there with title contenders like Feyenoord and Twente. Heracles and RKC, on the other hand, perform at the level of Feyenoord and Twente when playing at home, but are just plain mediocre on the road with exactly average away RSR’s.

Another outlier is Vitesse. They only foreign-owned Dutch club are presently second in the league table, but their RSR does not indicate they earned that spot through the quality of play. Their home RSR is 7th in the league, but only league numbers 17 and 18, Roda and Willem II perform worse than Vitesse does on the road.

In the end
In two consecutive posts, we’ve demonstrated how RSR can be used to separate both offensive and defensive strength, and home and away strength. In the next post we will combine these two elements and come up with some interesting food for thought as not all teams strike the same balance between offense and defense when play home or away.
Oh, and the answer to the initial question, NAC’s home RSR and Ajax’ away RSR are both 0.48.

Data provided by Infostrada Sports

Separating offensive and defensive performances

2 Replies

What makes Heracles and RKC the two extremes of the Eredivisie? What area does Marco van Basten need to work on at Heerenveen? Why does PSV stand out from the rest of the title contenders? And why is Vitesse not a true contender for the title?

The recently introduced method of computing Relative Shot Rates allows us easy answers to all of these questions. This method allows to separate offensive from defensive performances by looking at relative numbers of shots created and conceded.

Why are shots better than goals?

The simple answer is that shots are nearly ten times more frequent than goals. This means that it takes much more time to collected enough data when studying goals instead of shots. The average amount of goals scored by an Eredivisie team is around 1.6 per match, while the average amount of shots is around 13. In other words, the amount of shots during the 5th match round equals the amount of goals at the end of a 34-match season.
We know that converting shots into goals and preventing your opponent from doing so is a skill that is hard to repeat. Superior teams don’t separate themselves from inferior teams with regards to shots conversion and saves percentages, but simply by creating more shots and conceding less.

Why the relative amount of shots?

So, better teams create more shots and concede less. It’s no secret that some teams excel by creating shots, while other specialize in conceding less, but the it’s only the top teams that combine this skill.
However, by only looking at the absolute amount of shots, another problem creeps up.
Suppose that your team is a relegation favorite and you want to compare their total shot rate (TSR) to a relegation threatened rival team. Now, your team faces the league leaders early in the season, while the rivals only meet them near Christmas. It’s easy to imagine that your team’s shot rate over much of the first half of the season looks worse than their performance actually is. Only when the other team has also been thrashed by the league leaders the comparison becomes fair again. The Relative Shots Rate (RSR) compares the performance of a team with the performance of other teams that have played the same opponents. Details of this method were explained earlier.

The X-axis of the plot (horizontal) depicts the teams’ offensive performances, while the Y-axis (vertical) depicts the teams’ defensive performances. Note that the offensive performances show a wider range of variety than the defensive performances. For clarity, the defensive record is shown inverted, so that better defenses (that concede fewer shots) are higher in the graph. Better offenses are on the right hand side of the graph, so the upper right hand corner is the area of optimal performance, while the lower left hand corner shows the struggling teams.

It is immediately clear that PSV sticks out positively. They are matched in defensive terms by title rivals Feyenoord, and at a small distance Twente and Ajax, but PSV’s offensive record is second to none and allows them five shots per game more than even the best of the rest. The media runs a nice narrative of PSV’s defensive problems, but their defensive record shows that they are up there with the best of the Eredivisie.

An interesting position in this graph is RKC in the upper left hand corner. Erwin Koeman’s team takes a completely different approach compared to lower right hand corner Heracles. RKC matches the top teams in terms of limiting their opponent’s number of shots, but they pay for it by sacrificing their offensive chances to the level of relegation strugglers Roda, NAC and Willem II. Heracles, on the other hand, are second in terms of shots creation, but concede way too many shots in the process.

Van Basten’s Heerenveen has a situation that is quite comparable to Heracles. They can boost the third best offensive record, but only four Eredivisie teams give up more shots, which illustrates the imbalance in their team. Expect teams like Heerenveen and Heracles to be involved in high scoring matches, like Heerenveen’s 4-4 draw today, and expect RKC to play in low scoring affairs.

So, why is Vitesse not a true title contender? See for yourself, their offensive record is slightly above average (+0.25), but they concede 0.67 shots more than the average Eredivisie level. Expect Vitesse to regress as the 2012/13 Eredivisie comes near its end. Their overachievement so far will probably propel them into a play-off position, but be cautious to expect more on the basis of their present shot records.

In the end

We will regularly revisit this Relative Shots Rate concept, as it seems the best way to asses team performances. Studying shots rather than goals provides a much more solid base by generating nearly ten times higher numbers. On top of that, the Relative Shots Rate eliminates the bias that is otherwise always introduced due to differences in strength of schedule.

Next up: separating home and away performances…

Introducing the ‘Relative Shots Rate’

8 Replies

It has all kind of characteristics to make it both in the wide world of football blogging, and in the even wider world of football journalism. The Total Shots Rate, or TSR, is simple and easy to explain and it requires little data. Yet so far it is the single most powerful predictor of future performance of football teams.

TSR

For those not yet aware of the concept, let me explain shortly. TSR is simply the fraction of shots created by a football team in a single match, or over multiple matches. If Feyenoord creates 10 shots against Ajax, while Ajax creates 20 shots in that same match, Feyenoord’s TSR will be 0.333 and Ajax’ TSR will be 0.667. The total TSR over a single match will always be 1 and since two teams divide that total, average TSR’s of all teams in a league will always be 0.500. Over multiple matches, simply add together the number of shots created by your team and divide by the total number of shots in those matches.

But despite being the most powerful predictor around, TSR has it’s disadvantages too, with the most obvious one being that it does not correct for strength of schedule. The best teams in a league generally have a TSR of around 0.700, while at the lower end of the table TSR’s of 0.350 are more common. So the better teams seem to be around twice as good as the weaker teams with respect to generating shots. This leads to considerable bias throughout the season, as teams experience a different spread in strength of the opponents they face, but at the end of the season, when all teams have played each other twice, most of this bias has disappeared. The only bias remaining comes from the fact that teams don’t play against themselves, so the best team does not play the best team, while the weakest team does not play the weakest team. So better teams face on average lower TSR opposition compared to weaker teams.

Model

At 11tegen11, we’ve introduced a model to predict the final standing of the Eredivisie table based on TSR. Since shots are nearly ten times more frequent than goals, the model identifies better teams much faster than the regular league table does. The main problem with the model is that teams have different strengths of schedule. After fourteen matches have been played, PSV tops the Eredivisie table in terms of TSR with 0.730. But before the first half of the season is over and all teams have faced each other once, they still have to play Ajax (0.560), Twente (0.559) and N.E.C. (0.498). So it’s safe to assume that their TSR of 0.730 will fall over the coming three matches. Meanwhile, Heerenveen (0.469) still has to play Willem II (0.385), Roda (0.353) and Utrecht (0.544). So Heerenveen’s TSR will likely be an underestimation of their true strength.

Relative Shots

In order to tackle this problem, we will introduce the ‘Relative Shots Rate’, or RSR. The RSR is computed by comparing the number of shots created by a team against the average number of shots created by all teams in the league against that same team. This compares the performance of a team in a certain fixture with how all clubs have performed in that same fixture. Thereby correcting for the strength of schedule.

So, Ajax concedes on average 8.0 shots when playing at home, and VVV created 4 shots in Amsterdam. This gives VVV’s offense a -4.0 for that match. Meanwhile, VVV concedes 17 shots in that same match, against a league average of 13.6, so VVV’s defense record for that match is -3.4. If you would do this for every match played, and then add a team’s offense en defense record separately, you get an overall offense and defense performance that represents the average amount of shots that a team creates or conceded compared to league average.

Over fourteen matches, PSV has created on average 5.95 shots more than league average, while they have conceded 3.59 shots less. Now, these numbers can be converted to a single parameter that we will call the ‘Relative Shots Rate’, or RSR.

Computing the RSR

The average number of shots in a 2012/13 Eredivisie match has been 12.71. So, against the average opponent, one can expect PSV to create 12.71 + 5.95 = 18.66 shots and PSV can be expected to concede 12.71 – 3.59 = 9.12 shots. So the best estimate for shots when PSV plays an average league opponent would be 18.66 shots created by PSV and 9.12 shots conceded by PSV. This translates into a RSR for PSV of 18.66 / (18.66 + 9.12) = 0.672.

Now, we’ve learned that PSV’s TSR of 0.730 is quite a lot higher than their RSR of 0.672. This should indicate a strong series of fixtures coming up before the season is at its half-way stage. And indeed, with Ajax (RSR 0.554), Twente (RSR 0.538) and N.E.C. (RSR 0.486) still to play, PSV likely won’t maintain their TSR as high as 0.730.

As mentioned above, Heerenveen have three relatively easy fixtures coming up before the half-way stage of the season, playing Willem II (RSR 0.402), Roda (RSR 0.393) and Utrecht (RSR 0.536). So Heerenveen’s TSR of 0.469 is likely to be a slight underestimation of their strength.

In the end

So, while TSR is more straightforward and easier to explain, RSR offers a better representation of a team’s strength. It eliminates the bias of strength of schedule, and also allows to correct for situations where teams have played more home or away matches. On top of that, it is possible to create separate RSR’s for home and away matches, but we will save that for a later post…

TSR minus RSRGreen = underestimated by TSRRed = overestimated by TSR

Shot data provided by Infostrada Sports.

What if Wilfried Bony was a professional cyclist?

9 Replies

Make no mistake, I think that he is a good player, and that he probably is a very good player, but Vitesse striker Wilfried Bony is not the world-beater that people take him for. The Ivory Coast striker is presently the hottest player in the Eredivisie, thanks to his impressive return of 15 goals in 14 matches. Not bad, is it?

But, join me here on a slightly weird thought experiment.

Cycling

Imagine if Wilfried Bony would not have been a professional footballer who scores goals for a living, but a professional cyclist instead. After racing in his home country where his talent was quickly recognized, he transferred to Europe to develop further at continental cycling level for a few years, which represents his years playing football for Sparta Prague between 2008 and 2010. After that, he joined a World Tour team, which represents his transfer to the Eredivisie, and the cyclist Bony had a good first season there.

Now suddenly, in his second season at Vitesse, results have really picked up and Bony seems twice as good as last year, may be even the best cyclist in the entire peloton. The cyclist Bony would immediately get linked to rumours of illegal substance use or, to say the dreaded word out loud, doping.

Now, as far as we know, performance enhancing drugs don’t exist in football, or at most they play a marginal role. But in our thought experiment they do, and they go by the name of ‘luck’. The doping that caused the cyclist Bony to perform twice as good in his second year at the club is the luck that caused the football player Bony to temporarily perform at the level he does now for Vitesse.

Luck

There are certain parallels between doping in cycling and luck in football, which make it easier to assess the role luck plays in football. Doping has the potential to turn a decent professional cyclist into a good one, or a good one into a true world beater. It won’t turn an amateur racer into a World Champion. Luck has the potential to turn a decent striker into a good one, or a good goal scorer into a world beater. So our cyclist Bony performs significantly above his usual level for as long as the doping effect lasts, and our striker Bony converts way above his usual rate, for as long as his luck lasts.

But taking doping is a deliberate choice, while one can’t control luck. So, think of luck in football as cycling’s doping, but without any control over timing and dosage. Oh, and luck is not illegal as well, as all competitors have equal excess to it. In the case of Bony, this thought experiment helps to point out why his present goal scoring rate won’t last, as the amount of luck he currently experiences is not going to last.

Prior to this weekend’s match, where he scored the winning goal to hand PSV a rare Eredivisie home defeat, Bony had scored 14 goals in 13 matches, having played a total of 1115 minutes. That averages a goal every 80 minutes, which is a truly elite number.

GP = games played ; Sb = subs ; Min = minutes played ; Gl = Goals ; Sht = shots on target

His 14 goals, however, came from just 20 shots on target, for a conversion rate of shots on target into goals of 70%. Out of this world? Yes! Sustainable? No!

25 goals

There are broadly two numbers to compare Bony’s conversion rate with. First there is the normal conversion rate for all players alike, which stands at 30% over the present Eredivisie season. And second, there is Bony’s individual conversion rate prior to this season, which stands at 40 goals from 104 shots, or 38% for his entire career, including his time at Sparta Prague. Or third, we could take his individual Eredivisie conversion history, which stands at 15 goals from 46 shots, or 33%.

Both standards for comparison are nowhere near Bony’s present luck-infused 70% conversion rate. But how many goals can we expect Bony to score over the remainder of the season?

The best estimated guess for Bony’s total goals at the end of this season would be to hold his usual Eredivisie conversion rate of 33%, which is well in line with other quality strikers, against the expected number of shots on target that he will take for the remainder of the season.

Extrapolating on the amount of matches still to be played, and his (and his team mates’) capacity of generating shots on target, we can expect Bony to take 32 more shots on target. This would most likely give him around 11 more goals, one every 171 minutes, rounding off his season total at a respectable 25 goals.

Keep this in mind when judging short term performances. Just like doping in cycling, luck catches up quickly, and both of these performance enhancers are never there for the long run!

Statistics provided by Aaron Nielsen (@ENBSports). Check his site too!

Feyenoord 2 – 2 Ajax: An action packed ‘Klassieker’

1 Reply

A Feyenoord academy graduate scoring the opening goal on his debut, two come-back goals, tactical tweaks, a sending off and a late ‘golazo’ to equalize the score in the final minutes… Some matches just have it all. This year’s edition of ‘the Classic’ Feyenoord – Ajax was an action-packed affair.

Feyenoord’s 4-3-3

The starting line-ups.

Playing without the injured Schaken, Cissé and Goossens, Ronald Koeman opted to start academy graduate Jean-Paul Boëtius in the left wing. In earlier matches this season, Koeman had opted for a 4-4-2 in the absence of several offensive players, but against Ajax he would have wanted a broad screen of pressure that the rather flat nature of a 4-4-2 could never have offered.

Ajax’ new found 4-3-3

Unchanged in comparison to the win over Manchester City, just a few days earlier, Ajax fielded Christian Eriksen in a deep-lying striker role and kept captain Siem de Jong in midfield. Tobias Sana was again preferred over Derk Boerrigter.

Pressure and a false nine

The story of the first part of the game definitely evolved around the principle of applying the right amount of pressure. We’ve seen in the Ajax vs Manchester City match that when allowed the space to build from the back, Ajax can be difficult to play against. City’s narrow 4-2-3-1 allowed Ajax easy ways out from under the central pressure and both full-backs showed their on-the-ball skills.

Just like Ajax’ earlier Eredivisie opponent’s have generally tried to do this season, Koeman made it clear that he demanded early pressure from his team. With their three men up front they pressured Ajax’ back line, and work horse Lex Immers was ever close to prevent Ajax from circulating the ball through Poulsen in central midfield.

The problems for Feyenoord early in the game arose from those instances where Ajax somehow found a way around the first line of pressure and succeeded in finding midfield players De Jong and Schöne. With Eriksen playing the false nine role, Ajax could overload the area just in front of the central defenders that is normally covered by the holding midfielder in a 4-3-3, Jordy Clasie in this case. However, Clasie was overloaded by the presence of Eriksen and the nominal two offensive Ajax midfielders De Jong and Schöne. Meanwhile, Babel and Sana took turns to fill in the central offensive zone, which in turn offered space on the wings for Ajax’ full-backs to advance into.

Theoretically, Feyenoord had two options to dealing with this situation. They could withdraw one of the central midfielders to about the level of Clasie and protect the back four with a double pivot. This would deny Eriksen the playing space that he would need to exert any danger, but it would also limit Feyenoord’s power to press Ajax early on.

The other solution would be to have one of the central defenders step out of the back line and track Eriksen in deeper positions. However, this would allow Ajax the chance to try and exploit holes in what would then temporarily become a back three. Think of overlapping runs from midfield, like the opening goal that Schöne scored against Heracles last week, or inside forward runs by Babel from the left wing.

Initially, Feyenoord failed to apply any of these solutions and they paid the price on Eriksen’s opening goal. The Danish youngster used his ambidexterity very well in controlling the ball while running at high speed and finished off a move where his deep position allowed him the space to run at De Vrij. Later on in the game, De Vrij would follow Eriksen deeper into the midfield and this false nine phenomenon was much less of an advantage to Ajax.

Feyenoord’s direct game

With Ajax’ false nine granting them an extra man in central midfield, Feyenoord’s reply was a very direct passing game that involved Graziano Pellè in an important role as target man striker. The physically strong Italian proved difficult to play for Alderweireld and Moisander, with the latter even on the receiving end of a (softly given) second yellow card late in the second half. After the early opening goal, Feyenoord involved their full-backs much better, and found ways to play either lateral from Ajax’ packed central midfield, or just plain over it, directly seeking target man Pellè.

The first half equalizing goal was scored by 18-year old Dutch Under-19 international Jean-Paul Boëtius, who finished off a Wesley Verhoek that Lex Immers should have placed in the back of the net already. Another slight tweak that gave Feyenoord more options was that they played slightly deeper in possession, opening up more space for Clasie to work in.

The second half

The line-ups just before Feyenoord’s second equalizer.

Only minutes into the second half, Ajax scored from an indirect free-kick, as Siem de Jong connected on Eriksen’s cross. This started a period of patient possession play by Ajax, who looked to waste time in a perfectly allowed way, while Feyenoord increased their urgency with an even more direct approach.

The turning point of the second half was definitely the sending off of Moisander. Although this particular card was given quite easily, the Finish international already has a track record of receiving one yellow card per four to five Eredivisie games, totaling between 6 and 7 over the past seasons. Moisander already seemed firmly on track with four cards in Ajax’ first six Eredivisie matches of the present season.

Feyenoord switched to a 3-4-3 formation, with Achahbar for Mathijsen and De Boer replied by going 4-4-1, hoping to soak up the pressure. Mitchell Dijks completed the back four, with Schöne out, Babel up front and Eriksen pulled back to midfield.

Encircling Ajax under intense pressure, Feyenoord got the equalizer that their 11v10 dominance deserved. Graziano Pellè, who had been playing to set his team mates up all ninety minutes so far, took control of a cross from an indirect free-kick and scored a true golazo by firing in the volley on the turn, leaving Vermeer without a chance.

In the end

An action packed affair, that’s what this year’s first edition of the ‘Klassieker’ was. Initially, Ajax looked to take full advantage of their false-nine striker, but later on Feyenoord dealt much better with this challenge. The two sides looked very different in terms of style, with Ajax playing their typical controlled passing game, firmly taking hold of the centre of the pitch, and Feyenoord playing very direct, making use of the wide areas and fully exploiting the qualities that striker Pellè offers them. A draw should be counted a fair result as Ajax conceding two equalizers in two consecutive Eredivisie matches.

Last season, Ajax took 34 single goal leads, of which only 7 (21%) were defended unsuccessfully. This season, to date, Ajax has taken 12 single goal leads, of which 6 (50%) were defended unsuccessfully. Small numbers, but still, there may be something in it…

Ajax 3 – 1 Manchester City: Smart tactical move helps Ajax win first Champions League points

1 Reply

With a nice tactical twist by Frank de Boer, Ajax turned the score around to beat Manchester City 3-1 after conceding the first goal. Goals by captain Siem de Jong, Niklas Moisander and Christian Eriksen earned Ajax’ first points of the Champions League campaign and put City’s future in this competition in severe doubt.

Ajax’ 4-3-3 that was a 4-5-1

The starting line-ups.

Although not known for his tactical flexibility and tweaks during matches, De Boer has shown in this year’s edition of the Champions League to be well able to adapt his team’s playing style to the formidable quality of the teams that Ajax has faced so far. Against Dortmund and Real Madrid, Ajax operated very deep, with Ryan Babel as the sole true offense player in a target man role in a formation that turned out to be a deep 4-5-1 under offensive pressure.

Today, however, De Boer fielded a novelty, at least for Ajax, in a different way to try and solve the same problem. Today Ryan Babel came in from the left wing, with Christian Eriksen – only 20 years of age, but with 155 (!) senior matches under his belt already – playing a deep-lying striker role, reminiscent of the false nine principle, frequently helping out in midfield during City’s possession. Captain Siem de Jong added physical presence to Ajax’ midfield and provided overlapping runs from midfield where possible, in line with the false ten concept. On the right wing, 23-year old Tobias Sana, a new signing this summer, will have aimed to improve on being the defensive liability in his difficult first two Champions League outings, but only half and half succeeded at that.

Manchester City’s 4-2-3-1 that became a 4-4-2

The versatility of this Manchester City starting eleven is huge. Not just in terms of different players available, but just with a midfield four of Barry, Milner, Yaya Touré and Nasri, City started with an XI able to play 4-4-2, 4-2-3-1, 4-2-2-2 or any cross-over between these. Tonight it started out as a narrow 4-2-3-1 formation, but switched to a more orthodox 4-4-2 during the first half. As always, their offense rotated and switched positions frequently, with all three of Dzeko, Aguero and Nasri showing up in striker or wide forward positions at times during the first half.

The first half

Ajax started the game quite positive, in line with Frank de Boer’s quote before the game that “a draw would be useless…” With City playing compact in their narrow 4-2-3-1 formation, Ajax proved able to circulate the ball, but couldn’t quite penetrate City’s half yet. With remarkably advanced full-backs given the otherwise defensive adaptations installed, Ajax proved able to find space in wide areas. Both Blind and Van Rhijn were frequently left in acres of space by City.

In defense, Ajax’ formation frequently changed to a 4-1-4-1, with striker Eriksen withdrawn in midfield and Ryan Babel moving inside to the striker zone. In this regard, the choice to switch Eriksen and De Jong from their usual roles worked quite well. Eriksen was able to pick up balls at feet in his beloved central offensive area and the young Dane fired in two of Ajax’ first shots of the game. Meanwhile, Siem de Jong contributed to Ajax’ physical presence in midfield and proved essential in Ajax’ first goal of the game.

Despite Ajax’ dominance in wide areas, it was City that opened the score. Ironically, with Ajax’ full-back being very involved, the first offensive contribution from a City full-back initiated the move. Micah Richards played a delicious through-ball to exploit a distance between Ajax’ centre-backs that would never have been termed a gap at Eredivisie level. His pass set free James Milner, the ball was circulated wide and Nasri fired in coolly in the far corner.

After taking the lead, City attempted to strengthen their wide areas by switching from the narrow 4-2-3-1 to a genuine 4-4-2. Central midfielders Barry and Touré still sat a bit deeper than the rest of the midfield, but Nasri at the left and Milner on the right side provided more cover for their full-backs. At least, in theory they should, but as tracking overlapping full-backs has never been Nasri’s strength, Ajax kept on finding space on their right wing.

Exactly this space proved vital in the build up to the equalizing goal. Captain Siem de Jong set off a move that was in fact a very long distance one-two pass with right full-back Van Rhijn, to finish the move with a well-controlled one-touch shot from just outside the box.

The second half

In the second half, just before conceding the third goal, City lined-up in a 4-4-2 that was a 3-4-1-2 in possession, with Nasri drifting all over the pitch and Milner and Kolarov bombing forward in wide areas.

Having conceded the equalizer on the brink of half-time, different questions were asked of City in the second half. Knowing that only a win would keep their hopes of qualifying alive, they significantly increase the stance of their back line. This, combined with the fact that Ajax kept the line as high as they normally do, ensured a game played with much more urgency than before.

Ajax did concede possession earlier and City indeed had a few chances, but it was Ajax that grabbed the lead. Niklas Moisander, a summer signing from AZ Alkmaar, headed in at the near post from a well-struck corner by ‘Man of the Match’ Christian Eriksen. Just ten minutes later, as City was getting ready to build the pressure, Ajax had the luck that had escaped them earlier in this Champions League campaign as Eriksen saw a deflected shot fly in for the 3-1 score line. However, this move was initiated by decent early pressure that allowed Schöne to win a dangerous turnover deep in City’s half.

Gung Ho

Now trailing by two goals, Mancini gradually threw on his full strike force. Just before Eriksen’s goal, he had already introduced wing-back Kolarov for Lescott, but near the end of the match the full forces of Dzeko, Aguero, Balotelli, Tevez and Nasri were fielded together. This left the midfield in the hands of just Touré centrally with wide support of Kolarov and Clichy.

Spaces were wide open on City’s side of the pitch, but Ajax failed to extend the score further, with Sana missing an excellent one-on-one opportunity. At the other end, both Dzeko and Nasri saw close range attempts either saved or go wide.

In the end

Despite Mancini’s in-game change of formation and his gung ho substitutions, the winning tactical move of this game was made before kick-off. Fielding Eriksen in a withdrawn striker role killed two birds with one stone. Siem de Jong provided the energy, work rate and physical qualities that would have been lacking with Eriksen besides Schöne in central midfield, and Eriksen provided excellent movement between the lines and made dangerous runs at City’s centre-backs.

But the most obvious battle during this match was City’s initial narrow formation versus Ajax’ wide overlapping full-backs. Blind and Van Rhijn regularly provided the outlet that was missing in earlier Champions League games and City allowed Ajax to escape their pressure in this way. Mancini did try to fix his wide areas, but despite the wealth of world class strikers thrown on the pitch, decent wingers would brought more pressure to Ajax.

Heerenveen 3 – 0 Groningen: Derby of the North decided in second half

Leave a reply

Heerenveen was the Derby of the North quite simply in the second half, but the score line covered up the fact that the first half was a quite close affair, with Groningen having a fair share of chances early on. Groningen’s direct passing to target man Zeefuik broke down in the second half and Heerenveen won the possession battle and the match.

The story so far at Heerenveen

As we’ve not looked into these teams this season, it may be useful to take a quick glance at their season so far.

Marco van Basten’s Heerenveen hasn’t seen the smoothest of starts. With their first win coming only seven matches into the season, at first glance Heerenveen seem to do exactly what last season’s PDO analysis expected them to do: disappoint. However, this sells Van Basten’s work short, as their Total Shot Rate (TSR) has improved compared to last season and it has mainly been last season’s overachieving in finishing that Heerenveen obviously couldn’t reproduce this year around.

Anyhow, Van Basten had responded to the initial disappointing results by temporarily switching to an Eredivisie unusual 5-3-2 formation in an attempt to restore the balance, but switched back to a more reasonable 4-3-3 in this match.

Groningen’s season start

Just like their north Netherlands neighbors, Groningen have had a rough start to a new manager’s season. Robert Maaskant took over from Pieter Huistra, who paid the price for some bad luck in combination with slightly fading performances last season. Groningen’s start to the season had initially been somewhat disappointing, but their TSR was better than the results had shown and with two wins and a draw in their last three matches, luck seemed to have turned and Groningen had prior to this match risen to an eighth spot in the league table with more points taken than expected on the basis of adjusted bookmaker odds.

The formations

The starting line-ups

Both teams set out in what’s best described as 4-3-3 variants. All four wingers played quite wide roles, while most full-backs initially refrained from overlapping too much. This allowed the midfield three a pretty straightforward battle for the most crucial area of the pitch.

Both midfields were where the tactics showed the most difference. Groningen’s midfield is more defensive and out of possession oriented, with a double holding system, with passer Sparv in a deep position beside destroyer Kieftenbeld, while Michael de Leeuw is mostly involved later on, playing off target man Zeefuik. Heerenveen’s midfield seems more comfortable in possession, with Kums and Marecek capable of circulating short passes neatly, meanwhile covering up for Djuricic who is allowed a high degree of positional freedom in an advanced playmaking role.

Heerenveen’s defensive line stood a tad higher than Groningen did, which allowed them a territorial advantage, but this also allowed Groningen the opportunity to try and exploit the space in behind that defensive line.

The first half

Initially, the best chances of the game fell to Groningen, as they successfully exploited the space in behind Heerenveen’s defense. Combining target man striker Zeefuik with two quick men on the wings in Kirm and Schet doesn’t just work well in theory, it worked well in the first half of this match too. Zeefuik’s physical game forces Heerenveen to defend relatively high up the pitch in order to prevent Groningen from chipping balls in and connecting from there. On the other hand, the space they conceded in order to keep Zeefuik out, allowed Schet and Kirm dangerous territory to exploit.

Overall, the chances throughout the goalless first half were quite balanced. Heerenveen’s main threat normally comes when their possession flows through the delicate advanced playmaking skills of Filip Djuricic, but he was well marked out of the game by the energetic Maikel Kieftenbeld. And with both formations effectively matching each other all over the pitch, it was a personal duel that provided Heerenveen their best chances.

Groningen’s Leandro Bacuna has been used as a full-back by Maaskant for the past few matches now, but fails to make an impression here. He struggled big time to defend winger Rajiv van la Parra, and Heerenveen exploited this wing even more with some nice overlapping runs by full-back Raitala, with Groningen winger Schet not showing enough defensive awareness to consequently track his runs.

The second half

While the first half went down as a more or less balanced affair, this was certainly not the case in the second half. Groningen’s game plan, as said before, is primarily focused on using Zeefuik as a target man and build from there, and when the target man fails to win his duels, there’s nothing to build from. Groningen’s possessions became very short lived and Heerenveen grew into the game. Meanwhile, both teams seemed to have full confidence in their abilities to win this match and as a result, more risks were taken and more space was conceded.

This increase in space available mainly benefited Heerenveen. Their midfield is more adept at playing in possession than Groningen’s is, and with Gouweleeuw and Zomer winning their share of duels from Zeefuik, Groningen’s Plan A was effectively neutralized.

Fitting with the picture of the first half problems, Groningen conceded from a move that involved a crucial error by Bacuna. He simply allowed Van la Parra to come in front of him on a dangerous right wing cross by De Ridder and Van la Parra, the best Heerenveen player on the pitch simply converted from close range.

Only moments later the match was effectively over as Heerenveen capitalized on a simple pass that was incomplete in Groningen’s own half. This own half turnover allowed a quick break, Luciano conceded a penalty and Finnbogason converted.

Now, facing two goals down and seeing Plan A gone astray, Maaskant threw the dice and introduced an extra striker with Suk, thereby changing formation to a risky 3-4-3. After that, Heerenveen simply picked Groningen apart, there back three was exploited heavily on both wings and one of a series of good chances settled the final score at 3-0.

In the end

After a close first half, Heerenveen won the match with two goals in quick succession. Groningen saw their direct passing game break down as target man striker Zeefuik failed to win his duels in the second half and as a result, Heerenveen grew into the game. The final goal was the result of Groningen taking risks in a 3-4-3 formation, but overall the win was deserved for the home team. However, the 3-0 final score line covers up the fact that the first half was a close affair.

Romania 1 – 4 Holland: An important win with a secret return to two holding midfielders

Leave a reply

Holland played their best game in the second Van Gaal era to defeat Romania and earn an important win on the road to the 2014 World Championships in Brazil. Despite Van Gaal’s firm statement that he made in his early days as national manager that he would turn away from the supposedly ‘dreaded’ double holding midfielder system, the formation with both Nigel de Jong and Kevin Strootman in defensive midfield roles reminded secretly of Van Marwijk’s 4-2-3-1. With Rafael van de Vaart in a captain-worthy playmaking midfield role and the Dutch defense profiting from the much-needed extra midfield cover, Holland took an early lead and ran out fairly comfortable winners.

Holland’s 4-3-3 that was secretly a 4-2-3-1

Van Gaal made a few changes compared to the Andorra match just a few days ago. Right-back Van Rhijn and winger Narsingh were more or less like-for-like changes, coming in for Janmaat and Schaken. Up front, Robin van Persie was preferred over Klaas-Jan Huntelaar. Just like in the Andorra match, Rafael van der Vaart made another start with Sneijder out injured.

The starting line-ups

Two things deserve attention in this starting line-up. First, with both Nigel de Jong and Kevin Strootman in midfield, this is a flexible team. De Jong is surely capable of holding the midfield on his own in a true 4-3-3 system, but the versatility of Strootman makes a double holding midfielder system just as well possible. Tonight it was definitely the latter. Strootman’s defensive qualities were well on display in his chasing of Romanian midfielders, while his presence around the opposing box was hardly noticeable. Thus, a 4-2-3-1 would be just a apt to describe Van Gaal’s team today as the expected 4-3-3.

The second thing to note is the decision to play Van Persie rather than Huntelaar. In the build-up to Euro 2012 we’ve already made the case for Van Persie by pointing out that goals scored by the striker at hand are a bad parameter, but the most used nonetheless, to justify this choice. Much better would be to look at the performance level of the team as a whole. Van Persie offers a deeper-lying short passing game that proves invaluable in games against stronger opposition, or tricky away games like these. In this game too, his like-up play with the midfield proved essential in offensive building and he played a large role in setting off both wingers too.

Romania’s 4-2-3-1 system

With offensive midfielder Grozav playing quite close to striker Marica, and regularly overlapping him too, Romania played quite an interesting formation. All of the front four were eager to press early, yet both holding midfielders sat back most of the time. This resulted in Romania either winning possession early and in dangerous areas, or seeing this important first line breached and suffering the consequences. This phenomenon contributed to a very open first quarter of the game.

The first half

As said, the game sprung to life immediately. Romania’s early pressure split their team a bit and sometimes Holland played successfully past the first line of pressure and constructed attacks in the space between front four and back six, and at other times, Romania made early interceptions and set off nice moves themselves.

The opening phase contained some Dutch luck that proved pivotal for the development of rest of the game. Just a few minutes in, winger Gabriel Torje hit the underside of the bar with a neat long range direct free kick, while on the other side of the pitch, Jeremain Lens succeeded in opening the score with a long range header from a cleared corner that just fell below the bar and into the net.

Romania kept pressing fairly high, but in doing so they also committed quite a number of fouls, which both contributed to their frustration and to Holland’s chances to escape pressure through set pieces now and then. It was from another set piece that Bruno Martins Indi doubled Holland’s lead as he fired in a Van der Vaart free kick cross from close range.

Now facing a 0-2 score line, Romania threw some more pressure and some more energy into the match. At the cost of a foul here and there and with risky overlapping moves by both full-backs, they found their way back into the match. In his second match as captain, Kevin Strootman was largely to blame for not pressuring Marica on a central dribble and the Schalke striker found the back of the net from the edge of the box.

At the brink of half-time Holland earned a penalty when Narsingh was fouled on an incisive break-away. Van der Vaart crowned his excellent first half with the third Dutch goal here.

The second half

Not too much changes were notable from Romania’s approach through most of the second half. Their full-backs played a more offensive role with both wingers more narrow now and near the end of the game veteran striker Adrian Mutu game on as a second striker, but to hardly any effect as the Romanian midfield failed to reach him.

The main problem for Romania was not upfront, but one line behind, in midfield. The trio of De Jong, Strootman and Van der Vaart spent their energy smart in pressing the Romanian central midfielders and with Mutu playing effectively as a second striker, Holland had a 3v2 advantage in central midfield. On top of that, full-backs Van Rhijn and Martins Indi had the better of wingers Stancu and Torje. So, both centrally and in wide areas Romania could not reach Marica and Mutu enough.

In possession, Van der Vaart proved an essential element. His game covers such a wide area of the pitch that it is hard for opposing teams to prevent him from receiving the ball. Mark him out with a defensive midfielder and one of your midfielders is constantly dragged out of position, or limit his options with compact zonal defending and he will drop just that bit deeper or wider and still receive short passes at feet. Tonight, Van der Vaart had one of those game where he connected his team very well and this allowed Holland enough length of possessions to make easy left-to-right and defense-to-offense transitions.

Near the end of the match, Van Persie scored from an incisive Narsingh break-away to make it 1-4.

In the end

The score line of 1-4 is just a bit flattering given the fact that Romania definitely had their chances early on. It is just that chasing a quick double goal lead forced the home team into playing a more risky game than they had intended. Should Torje’s free-kick have landed just a tad lower and offered his team an early lead, Romania would never have been forced to throw their full-backs forward they way they did not. With pacy wingers Lens and Narsingh waiting to take advantage and Van der Vaart on song to glue his team together, Holland was never really under threat after gaining that early double lead.

Alternative league table: The Relative Performance

Leave a reply

In our series of alternative league tables, one element was clearly missing. We’ve started with the classic league table and added Total Shots Rates to identify high quality, sustainable performance. After all, a dominance in the number of shots created is the best parameter around to establish projected future success in football.

After the that, we’ve looked the same classic league table, but with added PDO rating this time. PDO, as regular readers will no doubt be aware by now, consists of a team’s saves percentage and conversion rate. Both of these tend to regress to mean with more matches added, so high PDO’s reflect non-sustainable high league standings, if performance levels in terms of TSR don’t increase. Low PDO’s reflect low league standings that are expected to improve over time if the same performance in terms of TSR is continued.

Using information from the TSR table, we use historical data to project the number of points that teams are expected to take from the remaining matches of the season and construct a projected final league table. This reflects what the situation at the end of the season will be like if teams are expected to continue their level of performance in terms of TSR and regress to mean levels of PDO.

A new addition here should be the relative performances league table.

This table below is fairly simple and the idea is not new. In a short amount of time, the same concept originated on different places, with Scoreboard Journalism being the first to write about this method. Using bookmaker odds, one can calculate the number of points a team is expected to take from a match. The total number of expected points taken is then compared with the actual number of points won and the fraction of these is the relative performance. An example of calculating a number of expected points and computing the relative performance is found below the actual table.

Let’s take the match odds from Match Day 8 game, Twente – AZ. Averaging the odds for most larger betting companies would see the odds for a Twente win at 1.71, for an AZ win at 4.49 and for a draw at 3.65. This indicates a 1/1.71 chance of a Twente win, a 1/4.49 chance of an AZ win and a 1/3.65 chance of a draw. These chances are 58% for Twente, 22% for AZ and 27% for a draw. The attentive reader immediately notices that these don’t add up to 100, and that has to do with the fact that bookies make their profit too!

So we have to degrade the odds a bit to make them add up to 100. Twente’s true odds would be 58 / (58+22+27) = 54%, AZ drops down to 21% and the draw to 25%. Now it adds up to 100. The expected number of points for Twente is 3* 0.54 + 1*0.25 = 1.87. For AZ this is 3*0.21 + 1*0.25 = 0.88.

Now, we add each team’s expected points over all matches played and compare it to the actual number of points won. The green and red bars present the fraction of expected points that a team has actually won. If this number is over 100%, a team outperforms the bookies odds so far this season. If this number is below 100%, a team under performs compared to expectations.

Data provided by Infostrada Sports.