When golfers lose a ball, they typically have to go back and search for it. This can take some time, depending on where the ball is located. In fact, many pro golfers lose more than one ball during a game. According to reports, Tiger Woods loses about two balls per round on average. Phil Mickelson is said to lose about three balls per round. Rory McIlroy, on the other hand, loses around four balls each round. It's interesting to note that some golfers seem to lose more balls than others. Woods and Mickelson are certainly two of the most well-known pro golfers in the world, so it's not surprising that they lose more balls than some of their counterparts.