Separating home and away strength

Logo_EredivisieWould 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).

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

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2 thoughts on “Separating home and away strength

  1. Mikkel

    Could be very interesting to see in the danish league where we play 12 teams – 33 matches. So youll have 2 home games against half the league and 2 aways with the rest.

    Reply

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