Play tennis long enough and there will undoubtedly be a time when you throw a fit on the court. You don't have to be a violent person or a hothead to have a McEnroe moment–it can happen to anyone. But the negative effects of on-court anger can be minimized if you come prepared to handle these situations.
First, identify and list the factors that have frustrated you in the past. It may be line calls, players on an adjacent court, a blister, anything that has made your blood boil. This will help you figure out, pre-match, the things over which you have little or no control. On court, you can eliminate those things from your thoughts and concentrate on the one element of the match that you can control, namely, your play.
Still, it's inevitable that at some point your game will falter and your temper will get the best of you. Once the frustration starts, you need to realize that you're having a meltdown. Too often, players don't even know they're losing it. Obvious behavioral outbursts such as racquet abuse, shouting or negative self-talk, excuse-making, and arguing with your opponent are all indications that it's time to cool off. If players continually fall victim to their emotions during matches, they should be videotaped and made aware of the warning signs. Also, coaches should stop play during practices and point out such emotional-control problems to their students.