Roger Federer's game can be confusing and unpredictable not only for his opponents, but also for the ball kids on court. That's what happened during the Swiss player's third round match against Filip Krajinovic in Indian Wells on Monday. The Swiss hit an amazing backhand slice after that the ball touched the net on his first serve. That slice first bounced on Krajinovic's side of the court, then Federer's. At one point, both ball kids were in the middle of the court trying to catch the ball.