I got an e-mail last week from Nate Gross, assistant men's tennis coach at Idaho State University. Nate authored several concise books on charting tennis matches and they are the best of this genre that I have ever read. While these books are user-friendly, accessible and elegant, I have to no intention of using them because I'm just not a big believer in the value of conventional, manual charting of tennis matches. You get data from charting like points won and lost, winners, errors, as well as serving location and percentages, but I'm not sure that this information is complete enough be useful. Observations are not analysis and data is useful only with context.
Let me explain …
All shots in tennis have three essential elements: Speed, Spin and Direction. Shot direction tends to get the most attention in charting because it's the most definitive (after all, the shot is either "in" or "out.") The other two elements, Speed and Spin, are not reflected in charting, and thus undervalued. Further, since tennis is highly interactive, shot outcomes need to reflect the ball hit from the other side of the net to be valid indicators of what happened. Some people make you play poorly.
Tennis performance is not devoid of context. Surely I will make more errors returning a ball that has tremendous pace, rotation and arc as hit by Rafa for example, than by a ball hit slower, with less spin and height. Conventional charting does not account for these shot variables. I can see my chart results now, "Steve made 81 unforced forehand errors yesterday against Rafael Nadal, but only four unforced errors today against John Smith. Maybe yesterday I just had a bad day or I just didn't listen to what the coach said?"
Even serving data might not stand alone as it could be impacted by my opponent. Perhaps I'm not fully recovered from being pushed around the court by rallying with a strong hitter and I lack full coordination or maybe I will attempt to compensate against a forceful opponent by "over serving" for example.
Furthermore, when we include subjective evaluations in our charting like the distinction between "forced" and "unforced" errors, the data gets even more murky.
Nevertheless, many coaches and players love to chart and find the information in these charts valuable. If so, look for Nate's book online at TennisMatchCharter.com. It's a five-star product. Conventional Manual Charting, however, is a one-star endeavor.
Steve Kaplan is the owner and managing director of Bethpage Park Tennis Center, as well as director emeritus of Lacoste Academy for New York City Parks Foundation and executive director and founder of Serve & Return Inc. Steve has coached more than 1,100 nationally-ranked junior players, 16 state high school champions, two NCAA Division 1 Singles Champions, and numerous highly-ranked touring professionals. Many of the students Steve has closely mentored have gone to achieve great success as prominent members of the New York financial community, and in other prestigious professions. In 2017, Steve was awarded the Hy Zausner Lifetime Achievement Award by the USTA. He may be reached by e-mail at StevenJKaplan@aol.com.