Our stats analyst Omair is already famous for his statistical articles and now he's inspired Ludolf, another reader of Women's Tennis Blog and fan of tennis numbers, to contribute his take on the WTA rankings, i.e. he compared the actual rankings with the performance of players at the biggest events – Grand Slams and WTA Championships. Enjoy!
The WTA ranking does not rank properly the strength of players in the sense of the ability to win a match or a tournament. The main reason is that it is cumulative and therefore underestimates players without a sufficient number of tournaments. We need to compute an average to avoid this. Moreover, the WTA ranking considers tournaments with weights not depending on the quality of players on them.
To achive the above-mentioned goal it seems to be more appropriate to take the average result from majors and the WTA Championships, the tournaments where the best players are almost always present. By the result of a player we mean the number of her losses (including the rounds which she did not achieve), i.e. 0 for the winner, 1 for the defeated finalist, 2 for defeated semifinalists, and so on. The results for the last 52 weeks are presented in the table, completed by the WTA ranking (after the Australian Open) for comparison. (FO: French Open, W: Wimbledon, USO: US Open, WTA: WTA Championships, AO: Australian Open)
It is not a surprise that Serena Williams and Kim Clijsters reached much better position than their WTA ranking. It should be noted that the average results of these players (and some others, too) are not relevant in the same degree as of the other players due to a small number of tournaments they took part in. For instance, had Kim Clijsters reached the next round at the French Open, she would have taken the 6th position with the average of 3.50. Also, Samantha Stosur and Agnieszka Radwanska got significantly worse result than their WTA ranking.
We can conclude that the first three players are significantly better than others, except maybe Serena Williams and Kim Clijsters. This is in a good correlation with the WTA ranking, which need not be true in general.
There are some weak points of this average result. First, rather small number of tournaments is considered, hence the average has a rather big deviation. This has been already pointed out for Kim Clijsters. Let us also note that the first three players have the smallest possible differences. Also, it does not describe the actual level of players but an average in past 52 weeks.
What do you think of this perspective? It's nice to have one more approach, but as Ludolf himself stated, it still has many flaws and the fact that only five tournaments are taken into account, it's pretty limited. Plus, almost all the best players showed up at the tournaments analyzed, but still it's "almost". (photo: © Neal Trousdale)