A few Sundays ago, someone on my court opened a fresh can of Wilson US Open tennis balls. Before a single ball was hit, it was immediately apparent that two of the three balls had a pronounced rattle. I made a video, which is embedded at the end of this post. If you listen carefully, you may be able to hear a woodpecker hammering in the background, seemingly responding to the sound of the ball. That woodpecker is our constant companion when we play on that field.
During one of the build-up tournaments for this year’s Australian Open, I noticed an off-court official systematically shaking each ball next to his ear as new cans were opened in preparation for the next ball change. He was clearly checking for rattling balls. It was surprising to me that these professional tournaments, with supposedly the best access to the highest quality balls from the manufacturer, had such strict quality control.
In my experience, internal rattles have become quite uncommon. Until a few weeks ago, it had been almost five years since I had even encountered this problem. I have a strong preference for the Wilson US Open ball, a premium product produced to tighter tolerances than other Wilson brand options. The Australian Open series uses Dunlop, which is honestly not my favorite. The result was that seeing an official bring each Dunlop to his ear for inspection gave a quiet sense of smug satisfaction that Wilson was clearly the superior choice.
So I’m convinced I manifested that rattling can of Wilson US Open balls last Sunday. The universe has a way of making that possible.
Of course, that naturally made me wonder why tennis balls rattle in the first place. What I discovered is that sometimes small pieces of rubber end up in the ball during or immediately after the production process. It doesn’t always happen, but when it does, the debris is normally so small as to be acoustically insignificant. However, occasionally a slightly larger fragment comes loose. The unmistakable rattle comes when those pieces hit the inside of the ball when it is hit, turned or shaken. Temperature fluctuations, shipping vibrations, or minor quality control issues can all contribute.
The manufacturers claim that this defect does not affect bounce or playability in any way. However, it is distracting and I don’t play with a ball that rattles. At a professional level, this is clearly unacceptable. That is why the official carried out the check. Because I am now sensitive to this happening, I will either see it happen all the time at professional tournaments in the coming months, or discover that the practice was unique to the Australian Open series.
I’m genuinely curious how often this internal dirt actually occurs. I wish there was a clean, controlled way to open a tennis ball without creating extra fragments in the cavity. My best idea yet, clamping it in a clamp and cutting it with a hacksaw, would almost certainly be messy and inaccurate. A scar on my left hand, caused by an ill-advised attempt to cut open a golf ball as a child, is a testament to the fact that safety should be the primary consideration for anyone tempted to experiment in that way.
In any case, the best opportunity to observe quality control at professional tournaments comes during first-round matches, which are streamed by the Tennis Channel, which keeps the cameras live during changeovers rather than switching to commercials. New balls are introduced after the first seven games and every nine games thereafter. However, they are sometimes opened one substitution earlier when the rotation corresponds to an equal game score.
So yes, the rattling balls are a thing, and it can happen with any brand, even the premium label Wilson. This doesn’t change my personal ball preference. One abnormal can doesn’t make up for years of consistent performance.
#tennis #balls #rattle