John Isner—the marathon man—set a record for the longest match in tennis history, and now he's set for a rematch with fellow record setter, Nicolas Mahut.
For a bigger player, John is a real threat for whoever plays him. He has a dominate serve, which allows for few opportunities for his opponents. However, John is still learning to play on grass. He tends to hit and bounce up his volleys, which doesn't work on grass.
If he plans on making the second week, John needs to bounce his volleys through and step up his game. Mahut is looking for revenge and last year's play strategy won't cut it.