Fuzzy logic: Why players check the ball before serving

A sport that has been around since the 12th century is likely to to pick up a few curious elements along the way and tennis has them in spades.

From its somewhat confusing scoring system of 15, 30, 40 (originating from using a clock as a scoreboard) to whether you can serve underarm (you can), tennis can leave first-time followers with questions.

One of the most frequently asked by casual fans is what are players looking for when selecting a ball with which to serve? The ball kids typically give three or more balls to the player as options. One is sent back to the ball kid, one is put in the pocket to use on a potential second serve and one is selected for the impending first serve.

What are tennis players checking for when selecting a ball to serve?

One of New Zealand’s top tennis coaches, Australian-born Clint Packer, told the Weekend Herald, before supporting Cameron Norrie at this year’s ASB Classic, that players look for the freshest balls with the least fuzz to select for their serves.

“If you’re a really strong server and you’re looking for power, you’re looking for a ball that’s newer or has been used less so the felt is a little bit tighter to the ball so you’re going to get more power,” says Packer.

The hair on a new tennis ball tends to be smoothed flat, while a ball that’s been hit around a bit will be more fluffy, therefore reducing speed through the air.

A player will therefore look for the two newest balls to serve, as they travel faster than an older ball, which should make it harder to return.

Packer says most players use this approach when selecting a ball, though there may be the odd occasion when a player selects a fuzzier ball if looking for a slower change-up serve or to take pace off the ball in the hopes of a longer rally.

The average speed of serve in professional men’s tennis is about 190-200km/h and 170-180km/h in women’s, meaning a slight improvement or reduction can be significant.

“A fresher ball can definitely get you an extra 20 per cent power, which is quite big with these margins. So it does make a difference.”

Balls are changed after seven games, then after every ninth game so there isn’t a huge amount of time for the balls to deteriorate. But Packer says different brands age at different speeds, as evidenced at this year’s ASB Classic.

“The one thing I noticed was the variation between the new and the old . . . I was talking to a couple of players [at the ASB Classic] saying ‘Wow, these are like bullets’ and it takes probably a dozen big hits, and then all of a sudden, it becomes fluffy, so the variation between the new and old, in my view, is a little bit more this year.”

The Association of Tennis Professionals (ATP) and Women’s Tennis Association (WTA), the two organising bodies of men’s and women’s professional tennis globally, have stated their intentions to move towards a standardisation of tennis balls used on the tours.

Historically, each tournament has had the ability to determine its own ball supplier or sponsor. This has led to potential inconsistencies of balls used week-on-week.

A review is under way with the goal “to deliver greater ball consistency within tournament swings for players and tighter certification and specification requirements for an enhanced end product, while not adversely affecting revenue streams for tournaments”.

Packer says while different balls perform differently, he believes oncourt conditions play a more important role in performance rather than ball selection, and therefore present a difficult issue for the tours.

“No matter what ball you have, like for example they’re using at the ASB Classic, might be really good in hot conditions, but at night, they might prefer another ball.

“That’s why I think the one-ball policy may be difficult, because the conditions play a massive part in how that ball reacts.”