In my latest post How predictable was EURO 2012?, I introduced 2 predictability measures, and in the preceding comment I came up with a third measure of predictability for a tournament like the EUROs.
All 3 measures are based on the FIFA/Coca-Cola Zonal Ranking for the members of UEFA (FIFA ranking). The latest ranking table before the finals reflects the general expectations in the model.
FIFA plain ranking
Pearson correlation between the final ranking and prediction based solely on the FIFA ranking, without taking group composition and tournament structure in to account. That is, the highest ranked team is expected to win the second highest ranked team is expected to become runner ups and so on. The final ranking is a 1 to 16 list of the qualified teams, based on (in given order)
a) final position or position in group,
b) points,
c) goal difference,
d) goals scored.
If two or more teams are equal, the previous stage of the tournament is consulted, to decide who has done best.
FIFA group dependent
Pearson correlation between the final ranking and prediction based on FIFA ranking under the constraints of the tournament structure and the group compositions. Zonal ranking has decided each round of the tournament, bases on zonal ranking difference in match or zonal ranking order in group.
FIFA prediction score
Apply FIFA ranking to the members of each group. Give score for how many teams were predicted to qualify for the knockout stage (x_1 of 8). In the quarter finals, reapply the FIFA ranking, and give score for how many teams were predicted to qualify for the semifinals (x_2 of 4). Repeat for the semifinals (x_3 of 2) and the final (x_4 of 1). This gives a total score of (x_1 + … + x_4)/15.
In order to determine whether the 3 predictability scores for EURO 2012 were high or low, we should compare them with their historical counterparts. I have done the math, and here is the result in a nice diagram (the sources are www.fifa.com/worldranking/ and www.uefa.com).
As the diagram illustrates, EURO 2012 scored highest in 3 out of 3 measures, which indicates that EURO 2012 has been at least as predictable as the previous 4 European Championships, if not the most predictable.
The diagram is quite interesting. Beside the above conclusion, that EURO 2012 in fact was predictable compared to the previous tournaments, it gives a lot of information about the strengths and the weaknesses of the different measures.
First, the FIFA plain ranking and the FIFA group dependent are closely related (the correlation measures). That should perhaps not come as a surprise, since the teams (beside the hosts) are seeded according to the FIFA ranking. I would say that the FIFA group dependent is most valuable of the two, because the tournament structure constraints are obeyed.
Second, EURO 1996, EURO 2008 and EURO 2012 displays the same pattern, the level of the FIFA plain ranking and FIFA group dependent is 0.2-0.3 points below the FIFA prediction score. EURO 2000 has very low correlation scores. The favorites France won, but many teams surprised a lot (Netherlands, Portugal, Turkey) or didn’t live up to the expectations at all (Germany, Czech Republic, Denmark) of the FIFA ranking.
The correlation measures give more (negative) weight to great disappointments than the FIFA prediction score, and the positive effect of the overall win of the favorites is not noticeable. The FIFA prediction score, on the contrary, gives very much weight to the overall win of the favorites, since they will add to the score in each round of the tournament. In 2004 it is the exact opposite. The overall winners Greece was ranked 13 out of the 16 qualified teams, so they had great negative impact on the FIFA prediction score because they surprised in all rounds of the tournament, and had relatively little impact on the correlation measures.
All 3 measures are based on the FIFA/Coca-Cola Zonal Ranking for the members of UEFA (FIFA ranking). The latest ranking table before the finals reflects the general expectations in the model.
FIFA plain ranking
Pearson correlation between the final ranking and prediction based solely on the FIFA ranking, without taking group composition and tournament structure in to account. That is, the highest ranked team is expected to win the second highest ranked team is expected to become runner ups and so on. The final ranking is a 1 to 16 list of the qualified teams, based on (in given order)
a) final position or position in group,
b) points,
c) goal difference,
d) goals scored.
If two or more teams are equal, the previous stage of the tournament is consulted, to decide who has done best.
FIFA group dependent
Pearson correlation between the final ranking and prediction based on FIFA ranking under the constraints of the tournament structure and the group compositions. Zonal ranking has decided each round of the tournament, bases on zonal ranking difference in match or zonal ranking order in group.
FIFA prediction score
Apply FIFA ranking to the members of each group. Give score for how many teams were predicted to qualify for the knockout stage (x_1 of 8). In the quarter finals, reapply the FIFA ranking, and give score for how many teams were predicted to qualify for the semifinals (x_2 of 4). Repeat for the semifinals (x_3 of 2) and the final (x_4 of 1). This gives a total score of (x_1 + … + x_4)/15.
In order to determine whether the 3 predictability scores for EURO 2012 were high or low, we should compare them with their historical counterparts. I have done the math, and here is the result in a nice diagram (the sources are www.fifa.com/worldranking/ and www.uefa.com).
As the diagram illustrates, EURO 2012 scored highest in 3 out of 3 measures, which indicates that EURO 2012 has been at least as predictable as the previous 4 European Championships, if not the most predictable.
The diagram is quite interesting. Beside the above conclusion, that EURO 2012 in fact was predictable compared to the previous tournaments, it gives a lot of information about the strengths and the weaknesses of the different measures.
First, the FIFA plain ranking and the FIFA group dependent are closely related (the correlation measures). That should perhaps not come as a surprise, since the teams (beside the hosts) are seeded according to the FIFA ranking. I would say that the FIFA group dependent is most valuable of the two, because the tournament structure constraints are obeyed.
Second, EURO 1996, EURO 2008 and EURO 2012 displays the same pattern, the level of the FIFA plain ranking and FIFA group dependent is 0.2-0.3 points below the FIFA prediction score. EURO 2000 has very low correlation scores. The favorites France won, but many teams surprised a lot (Netherlands, Portugal, Turkey) or didn’t live up to the expectations at all (Germany, Czech Republic, Denmark) of the FIFA ranking.
The correlation measures give more (negative) weight to great disappointments than the FIFA prediction score, and the positive effect of the overall win of the favorites is not noticeable. The FIFA prediction score, on the contrary, gives very much weight to the overall win of the favorites, since they will add to the score in each round of the tournament. In 2004 it is the exact opposite. The overall winners Greece was ranked 13 out of the 16 qualified teams, so they had great negative impact on the FIFA prediction score because they surprised in all rounds of the tournament, and had relatively little impact on the correlation measures.
Nice chart indeed!
ReplyDelete