Fiend at Court Unplugged
One of my favorite discoveries from 2020 was the fact that the US Open uses different balls for the men and women’s events. That fact was casually mentioned in this site’s discussion of the manufacture and construction of the tennis ball. In retrospect, that topic is worthy of a post devoted entirely to that fact. Today I am correcting that oversight.
The source of the separate balls practice cited in the original post on this site was a New York Times article written back in 2016. In the interim, I came across a more recent article that ran in the Wall Street Journal that contains additional details including some rationale for the practice.
At the US Open the women play with regular duty balls while the men use extra duty balls. This is based on a perception that the regular duty balls are “faster” which makes the women’s game more “exciting.” Apparently the men’s matches are fast enough already.
The only difference between the balls is the felt. In regular duty, the weave of the material is tighter and smoother. As a consequence, the ball doesn’t “fluff up” as much. With less felt, there is less ball surface to create drag when the ball flies through the air.
Wilson is the official supplier of balls for the US Open. If you want to amaze your family and friends with useless trivia, approximately 98,000 balls are provided to the tournament each year. That sounds like a lot, but it is just a drop in the bucket of the 80 million balls the company manufactures on an annual basis.
The US Open balls are somewhat special. In normal manufacturing Wilson uses 30 molds to make the rubber cores simultaneously during production. A much smaller number is used for the US Open balls, typically 2-3 molds each year. Thus, the US Open balls will be more consistent than balls available to the consumer. I have… never noticed any variation in Wilson Balls.
The US Open balls are also stamped with the tournament logo and the year. The Extra-duty men’s balls have the “Wilson” script in black and “U.S. Open” print in red. The Regular-duty balls used for the women are the opposite of that. It is the only way to visually tell the difference between the two balls.
The practice of separate ball types is exclusive to the US Open and hard court tournaments that lead up to that tournament. Tournaments in other regions, including the other three Grand Slams, use the same balls for the men and women.
The WSJ article makes the assertion that the use of regular duty balls is a requirement of the WTA Rule Book. Curiously, the WTA Rule Book that was cited by that article… does not include any such requirement and it wasn’t there in 2019 either. If there was a requirement, then other tournaments would probably also use separate balls.
From a personal standpoint, I have recently been using separate balls with one of my regular training partners as a COVID precaution. She provides a can of extra duty balls to each of our practice matches and I bring regular duty. That is an alternate practice to marking the balls for each player with a Sharpie. I am innovative and/or lazy that way. Take your pick.
Quite frankly, I have never perceived a velocity difference between the balls in use in those practice matches. Since I can sometimes approach “Princess and the Pea” levels on such matters, it is somewhat surprising to me that I have failed to notice a variation.
I am going to go out on a limb and say that the ball felt doesn’t make a perceptible difference for the majority of players.
- “Which Tennis Ball is in Use? It Makes a Difference“, Stuart Miller, New York Times, September 3, 2016.
- “At U.S. Open, Do Women Play With Faster Tennis Balls?“, Jo Craven McGinty, August 16, 2019.
This was the original mention of the separate balls practice from earlier in 2020.
