Date of Report[1]: Dec 11st, 2017

By Rubén A. Báez[2]

Full statistical report in pdf click here


General Performance Index (GPI): "It is an index that measures the performance that a tennis player has had in a period of time."


This index considers for its calculation several parameters such as: the number of matches played and won, serves, points won with the 1st and 2nd serves, returns, break points (saved and won) and tiebreaks.


The GPI is calculated monthly or annually and for each kind of surface (Hard, clay and grass) too. The database for its calculation starts from May 2012 to the present. The main idea is to be able to compare the performance of the tennis players in a homogeneous way, that is, in a period of analysis "t", compare the performance of the tennis player A versus the performance of the tennis player B and determine which of the two tennis players had a better performance in the period "t" (month, year, etc.). The general representation of the formula is:

GPI = f [Pi, t, s (H, C, G)]



Pi = parameters, for i between 1 and n

t = analysis period,

s = type of surface (H: hard, C: clay or G: grass). If this parameter does not appear in the formula, it is because it contains "all" surfaces.


Another way to present the GPI would be:

GPI = f [Pi, t]  GPI Total surfaces

GPI-H = f [Pi, t, s (H)]  GPI of Hard surfaces

GPI-C = f [Pi, t, s (C)]  GPI of Clay surfaces

GPI-G = f [Pi, t, s (G)]  GPI of Grass surfaces


The index has been tested and accurately exposes the order of the players performance. It is for that reason that we have put in the laborious work of calculating the GPI from May 2012 to November 2017. We will continue calculating it in the future and publishing it from now.


These indexes are designed for that analysts, coaches and tennis players can analyze them and draw out their own conclusions.  You will notice that many times there are players who have better GPI than other players with better ranking. I have tried to find explanations for this and, in my opinion, it is due, among other things, that many Top players win games without playing well, with poor performance regard the parameters, but win anyways (For example, playing well the important points). Of course, there are other reasons that explain these aspects and that are implicit in the statistics that are used for the GPI.


For the annual and monthly determination of the GPI, all the players who participated in the season have been taken, regardless only the Top 100 of the WTA ranking is shown in this report.


The used statistics to calculate the annual General Performance Index (GPI) come from:


a) WTA Premier Mandatory, Premier, International, WTA Finals y 125K Series Tournaments.

b) Australian Open, Roland Garros, Wimbledon, US Open.

c) Fed Cup.


The Olympic Games are included in the annual GPIs for the 2012 and 2016 seasons (not shown in this report).


This report exposes for the 2017 Season:


1) General Performance Index for all surfaces (GPI) - Table 1, page 5,

2) General Performance Index for Hard Surfaces (GPI-H) - Table 2, page 9,

3) General Performance Index for Clay Surfaces (GPI-C) - Table 3, page 13,

4) General Performance Index for Grass Surfaces (GPI-G) - Table 4, page 17.


Full statistical report in pdf click here 

[1] Report elaboration based on data from official Websites:

[2] Tennis Instructor (Argentine School of Tennis Instructors, Buenos Aires), Bachelor in Business Administration, Public Accountant, Post grade’s degree in Finance Management and Capital Markets, MBA (IAE Business School, Austral University, Argentina).




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