Feature Presentation (Page 1)

I want to thank Mr. Philippe Dore, the Ranking and Statistics Coordinator for the ATP Tour for taking the time to discuss his duties and the mathematics that he uses every day on the job. Philippe shared some interesting statistical trends and the technology that the ATP Tour is using for men's pro tennis tour players. This has become a very high tech endeavor and we wanted to share the story and of course "THE MATH" that goes into "adding it all up in tennis".

The ATP Tour coordinates the men's professional tennis tour and is responsible for computing the points, rankings and monetary amounts awarded to the players on the tour. The results from the week's competitions are all processed using electronic uploads, computers, statistical software and databases over the weekend so that the new rankings and statistics are available each Monday.

The database dates back about 25 years and holds 9300 players and 6000 tournaments! "Yes", Philippe said, "we do determine who is ranked as the best player, but the database holds much more information, than just who is Number 1". Philippe explained that rankings are used extensively by the media - television commentators, newspaper reporters, and more recently the tennis and sports web sites. "It's common to refer to the player and his ranking, but the rankings have a more practical purpose for the players. Their ranking may or may not qualify them for a particular tournament. If you are ranked above a certain point, say "100", you may be able to enter a particular tournament without additional qualification."

Statistics is the branch of mathematics that deals with the collection, organization, analysis and interpretation of numerical data. We asked Philippe, what types of statistics were collected by the ATP Tour? Everything you could possibly imagine: rankings, earnings and points for singles, doubles, and teams; statistics by age, country, and court surface; number of aces, double faults, 1st serve percentages , 1st serve and 2nd serve points won, service games won, break points saved, return of serve leaders, points won on the return of 1st serve or 2nd serve, break conversions, return games won ... the list went on and on and on ....

Once all the results are in the database, records like "Most Titles", best career ranks and win/loss records are calculated. And Philippe knew all the statistics! When he was asked "who leads in most points for the return of the 1st serve?", he replied "Agassi" in a split second with no hesitation!

So what type of educational background and skills are required to handle these responsibilities? A degree in mathematics for starters. Philippe has a degree in statistics from the University of North Florida and attended the university on a tennis scholarship. A lot of attention to detail is needed, you need to be meticulous and patient. As you can imagine, accuracy is critical - so much is at stake with rankings, points, and prize money!

What type of math is used? Clearly basic math: adding, sorting, counting, as well as calculating averages, means, standard deviations, regressions, curve fits, and percentages. Knowledge of the numerous varieties of graphic presentations - plots, pie and bar charts - is also essential. Although the computer and the statistical software that the ATP Tour uses does much of the tedious work, the statistician has to understand what questions are being asked, how to program those questions, and whether or not a result is a trend or just a coincidence.

For example, the average match time on a hard court is 1 1/2 hours - there is very little variation from match to match, tournament to tournament. The average time for a clay court match is also 1 1/2 hours, but there is a large variation from match to match even though it has the same average time as the hard court time.

In statistics, you can quantify this variation by calculating the "standard deviation" of the average hard court match time. For example, if the times for 5 matches on a hard court were 1 hour 25 minutes, 1 hour 27 minutes, 1 hour 30 minutes, 1 hour 33 minutes and 1 hour 35 minutes, the average would be 1 hour 30 minutes. You can see the match time does not vary by more than 5 minutes in either direction. Let's look at 5 clay court times: 50 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 2 hours 10 minutes. This also averages out to 1 hour 30 minutes - but you can see the huge variation in match time. We would say that the average match time on a hard court has a small standard deviation and the clay court has a large standard deviation. So although the press may never see a standard deviation, the statistician does a lot of "behind the scenes math" to validate trends.

How are all these numbers collected? How does all this work? The chair umpires have a "palm-top" computer where they record the match. After the match is over, the umpire goes to the official's room and uploads the information onto a supervisor's laptop . When the tournament is over the supervising official is responsible for the electronic submission of the information to the ATP Tour in Florida. The information from all the tournaments conducted that week are uploaded into a large database. The rankings come out over the weekend, so Philippe works every Sunday!

We asked Philippe, "Aside from the ATP Tour's obvious usage of the database for rankings, how else is this statistical data used?" He told us that officials and event coordinators use the information to schedule the matches and entire tournaments. For example, the average hard court match takes 1 1/2 hours, while the time for a grass court match is 1 1/4 hours. As well, agents interested in working with "up and coming" new players are often interested in the "stats" by age. Coaches will often ask for their players stats after a tournament match to evaluate performance.

Philippe told us the project he enjoyed the most was a recent study he conducted for a scientist from the ITF's (International Tennis Federation) technical committee. They were interested in trends that would correlate to racquet technology improvements. Philippe calculated the number of aces and the average match time on different surfaces over a period of time. Yes, match times are shorter and there are more aces!

Finally, we asked Philippe where he believes the technology is going. He told us, clearly there is more and more demand for statistics in the "information age". Especially with the popularity of the Internet and web sites, the demand for statistics has been greater then ever. As television coverage of the sport is becoming more technical, commentators want to integrate this information into their analysis of the game. One the most amazing innovations is a system that the ATP Tour has begun using in a collaboration with Lucent Technologies called LucentVision. The system has been used in Europe and is a real-time vision system that tracks and collects player movement.

For example, in the Corretja-Moya final of the ATP Tour World Championship in Hannover, Germany, the system determined that each player had traveled six miles during the match. In tennis that's like six miles of sprinting. World-class athletes sprint at 22 or 23 mph - some of the tennis players were moving up to 18 mph. Although its intended use is for television broadcasting the application for players and coaches is obvious! (Incredibly cool - definitely worth hitting the links!)

In practical matters, the Internet has made the electronic submission of tournament data much easier - but there are still tournaments held in small remote areas. It will be a time saver when all the tournament information is submitted online.

How does he see player statistics used in the next five years? Philippe told us, "the database contains information on a players performance at certain critical points in the game. For example, what did he do at 0-30? Does he consistently lose that point? Understanding these statistical trends can aid in evaluating a player's performance, isolating areas for improvement. The player and coach can enhance physical and mental training strategies to overcome these problem areas."

It was clear to us that Philippe Dore is a professional who has been able to meld his love and understanding of tennis with the technical know-how, vision and desire to contribute to the game. Again we thank him for his time and hope he has a good weekend - even though we know that he is working this Sunday!

Have you thought about "adding it all up for yourself" in tennis? Have a friend, coach or folks record your performance. As your tennis career advances you may be able to spot trends in your performance - both your strengths and areas for improvement.