Rod Laver, the only player in the history of tennis to wintwo Grand Slams, tells tennis players to “Know Yourself” in this lesson featured in his memoir “The Education of a Tennis Player.”

It’s fine and dandy to read about how Rod Laver and Ken Rosewall and Pancho Gonzalez do it, useful and worthwhile, I hope. There are shots that I may be able to help you with in this book. That’s why you’re reading it.

Nevertheless, there is one overriding fact of the matter when you get into a match: you are you. You have progressed to a certain ability in tennis, and you must be aware of this when you play.

It does no good to try to whack a topspin backhand in a difficult spot if you haven’t practiced it, or you are unable to make it work. The fact that I can escape with it doesn’t help you. You may be better off lobbing.

What I’m getting at is this: don’t try to play beyond yourself. You win tennis matches on the other guy’s errors and by keeping the ball going. You’re just aiding and abetting the enemy by trying to pull off the impractical or impossible shot in certain situations. If you’re pushed wide of the court, you’d better hit down the line or lob rather than trying a slick crosscourt that has only a slight chance of succeeding.

Wait for the opportunity to put your best shots into use, until you have the edge and the chances of success are high. Until then, work for that opening by getting the ball back to your opponent’s weaknesses.

Cut down on your mistakes. If you’re up against a strong server, don’t try to overpower him with your returns. Go all out against his weaknesses, not his strengths.

Take stock of your physical limitations. Don’t take unnecessary steps or run for balls on which you have little chance. If you don’t have a roaring serve and good volleys, don’t play a net rushing game.

Know what you can hit well, and when to use it. A little thought on the matter will tell you.

Sometimes you’ll be inspired. That’s the joy of the game. You’ll be hitting away like mad and everything will work. Fine. It’s most likely to happen when you start out solidly with the things you can do well, not trying to play above yourself. When you win some points and games that way, your confidence will expand.

Talk to any really good professional player and ask him how he plays me. “Keep the ball in play and let Laver make the mistakes,” the guy will say. “Laver does make mistakes.”

So, I reckon, will your opponent.