Tennis players reject balls before serving because they’re looking for the one that best suits the shot they want to hit. Every ball in play wears differently over the course of a set, and those small differences in fluff, firmness, and bounce add up enough to matter at the professional level. What looks like a quirky habit is actually a quick physical inspection combined with a bit of routine and superstition.
What Players Feel When They Squeeze
When you see a player bouncing and squeezing two or three balls before choosing one, they’re checking a few things at once. The most important is internal pressure. A ball that’s lost air feels softer and won’t travel as far off the racket. Players sometimes call these “dead” balls. If you can easily dig your fingers into the felt, the ball has lost too much pressure. On the other end, a ball with higher pressure feels overly bouncy and harder to control.
Beyond pressure, they’re feeling for how the rubber has changed shape. The rubber shell of a tennis ball becomes more elastic as it gets hit repeatedly. It stretches unevenly, loses its original tension, and starts to deform. That uneven wear makes bounces less predictable, because one side of the ball may be softer than the other. A player holding two balls can often tell immediately which one has taken more punishment just by rolling it in their hand.
Why the Fluff Matters
The fuzzy felt covering on a tennis ball isn’t decorative. It directly controls how much air resistance the ball encounters in flight. Research from Sheffield Hallam University found that raising or flattening the nap (the technical term for that fuzz) changes the ball’s drag by almost 6%. That’s a meaningful difference when serves travel upward of 120 miles per hour.
A newer, fluffier ball catches more air and slows down faster. A ball that’s been hit around for several games has its felt beaten flat, so it cuts through the air more easily and arrives quicker. This is why Roger Federer has said he wants the “fastest ball for the first serve.” He’s choosing the smoother, more worn ball because it will lose less speed on the way to the service box. Novak Djokovic has described the same preference: looking for a faster ball to maximize his serve.
For a second serve, where players typically want more spin and control rather than raw speed, a fluffier ball can actually help. The raised nap grabs the air more, which lets the ball curve and dip. So a player might reject a smooth ball on a second serve and pick a fresher one, reversing their first-serve preference entirely.
The Speed Difference Is Real
Research comparing new and used balls at the French Open confirmed what players instinctively feel. Used balls travel measurably slower, giving the returner fractionally more time to reach the incoming shot. That extra time makes it harder for the server to hit outright winners. The difference in rally pace between new and used balls was small in absolute terms, roughly a hundredth of a second, but at the elite level, points are decided by margins that thin. A serve that just catches the edge of a returner’s reach with a fresh ball might land cleanly unreturnable with a slightly faster, worn one.
This is also why tournament rules require ball changes at set intervals, typically every nine games after the first change and every eleven games after that. Once balls have been in play long enough, the cumulative wear flattens performance differences between them, and a fresh can resets the cycle.
Routine, Focus, and Superstition
Not every ball rejection is purely scientific. A New York Times feature on the ritual noted that the process is “built at least as much in superstition as in science.” Djokovic himself acknowledged he’s not sure the difference between two balls always matters physically, but added, “I’m convinced in my head that it does.”
That mental component is genuine and useful. The few seconds a player spends choosing a ball create a built-in pause between points. It’s a chance to exhale after a tough rally, reset mentally, and decide on a serving strategy before stepping to the baseline. Many sports psychologists view these micro-rituals as anchoring behaviors: small, repeatable actions that help athletes transition from reactive mode (playing the point) to deliberate mode (planning the next one). The ball selection process gives that transition a physical container.
Some players are far more particular than others. A few will cycle through four or five balls before settling on one. Others, like Federer, are relatively quick about it. But nearly every professional player does it to some degree, because even if the physical advantage on any single serve is tiny, the psychological benefit of feeling prepared and in control compounds over hundreds of service games in a season.
What They’re Actually Choosing Between
To summarize what separates a “good” ball from a rejected one in a player’s hand:
- Pressure: Too soft means less power and shorter distance. Too firm means unpredictable bounce height.
- Felt condition: Smooth felt for speed on a first serve, fluffier felt for spin and control on a second serve.
- Shape consistency: Unevenly worn balls bounce unpredictably, so players avoid any ball that feels lopsided or overly deformed.
- Mental fit: The ball simply feels “right” for the shot they’re planning, even if the physical difference is marginal.
The whole process takes just a few seconds, but it’s a compressed decision that accounts for aerodynamics, bounce behavior, shot strategy, and mental preparation all at once. What looks like a player being fussy is actually one of the quieter skill expressions in professional tennis.