Martin Kaymer has spent the first two days of the U.S. Open relentlessly tearing apart the fabled Pinehurst No. 2. How does a golfer prepare for such an epic task? By using a tennis ball, of course.
Prior to his round on Saturday, television cameras caught Kaymer warming up with a tennis ball around his neck, just as he's done at tournaments including the Masters. It's a little odd for a good luck charm, isn't it?
The tennis ball is actually a training aid, a handy way for Kaymer to keep his forearms close together in his backswing. Kaymer won the PGA Championship in 2010, and then fell off the edge of the earth as he tinkered with his swing for several years. But things are starting to click; just a few weeks ago, Kaymer won the Players Championship, and you've seen what he's done to Pinehurst the last couple days.
Kaymer uses the tennis ball as a way of keeping his stroke form in tune all the way through the backswing. The string is to keep the tennis ball from rolling away. Easy enough, right? Hey, if Kaymer wins this thing, expect those tennis balls to start showing up at every driving range across the land.