Don't Be Predictable

From Tony Lance, of TENNIS Magazine (http://tennis.com/):

You've played the same player a dozen times. At first you won most of the matches, but now your opponent has pulled even and even started to gain the advantage. Although neither of your games has changed significantly, there's been a shift in the balance of power and you're not sure why.

Most likely, your opponent has figured your game out and you haven't adjusted. When you suspect that this is true, it's important to:

Recognize your own patterns: If your backhand always goes crosscourt and your second serve unfailingly lands in the same place, you've become predictable to your opponent. Identify the plays that you use over and over again.

Change things up: Once you've identified your patterns, change them early in the next match. For example, instead of hitting your usual attacking forehand down the line, try a short-angle putaway or a drop shot (particularly if you're ahead in the game). And rather than aim every volley crosscourt, hit behind your opponent a few times to throw off his anticipation.