Now that we are in the midst of Wimbledon, it’s important to realize that the defensive requirements on grass are far different from the defensive requirements on clay. These differences carry noticeable implications for the players.
The Ability to Slide
On the slicker, more slippery grass, the ability to slide is drastically reduced. It’s also significantly riskier, particularly at the beginning of any grass-court tournament.
On clay, the ability to slide is much easier and is an essential element of moving on the surface.
Players who have an edge on grass are able to slide with extreme effectiveness. The most notable example of this is Novak Djokovic, whose open-stance defending has propelled him to three Wimbledon titles. Nadal, who relies far more on sheer footspeed to play defense, does not slide as well on grass and, as a result, does not defend as well on this surface.
A vital element of defending on grass, especially off the return and against players who are serving and volleying, is being able to keep a compact backswing. On clay, players have more flexibility to produce longer swings and take bigger cuts at the ball, due to the court speed being significantly slower.
Players with longer swings, such as Dominic Thiem, have a tougher time playing from neutral and defensive positions, since they are forced to alter their swing paths in a manner they are not accustomed to.
Adjustment To The Contact Point
When defending on grass, players are going to deal with balls that provide them significantly lower contact points. On clay, with players attempting to play with more margin, height and spin, the contact points from defensive positions are going to be substantially higher.
Players with more extreme grips are going to have a tougher time getting their racket square to the ball on grass and will be susceptible to underspin and flatter, lower-lying shots. In the second round, Kei Nishikori, who plays with a western grip, will have his hands full against Bernard Tomic, who will provide a heavy dosage of underspin shots to the Japanese.
The one advantage of defending on grass is that if you can do it effectively, the points are going to be shorter. Defending will not be as physically taxing. On clay, defending is certainly more physically taxing. The defenders have more time to respond, but that means the points are going to be longer.