If you are playing a very steady man, do not strive to beat him at his own game. He is better at it than you in many cases, so go in and hit to win. On the other hand, if you find that your opponent is wild and prone to miss, play safe and reap the full crop of his errors. It saves you trouble and takes his confidence.
ABOVE ALL, NEVER CHANGE A WINNING GAME.
ALWAYS CHANGE A LOSING GAME, since, as you are getting beaten that way, you are no worse off and may be better with a new style.
The question of changing a losing game is a very serious thing. It is hard to say just when you are really beaten. If you feel you are playing well yet have lost the first set about 6-3 or 6-4, with the loss of only one service, you should not change. Your game is not really a losing game. It is simply a case of one break of service, and might well win the next set. If, however, you have dropped the first set in a 2 out of 3 match with but one or two games, now you are outclassed and should try something else.
Take chances when you are behind, never when ahead. Risks are only worth while when you have everything to win and nothing to lose. It may spell victory, and at least will not hasten defeat. Above all, never lose your nerve or confidence in a match. By so doing you have handed your opponent about two points a game—a rather hard handicap to beat at your best.
Never let your opponent know you are worried. Never show fatigue or pain if it is possible to avoid, since it will only give him confidence. Remember that he feels just as bad as you, and any sign of weakening on your part encourages him to go on. In other words, keep your teeth always in the match.
Don't worry. Don't fuss. Luck evens up in the long run, and to worry only upsets your own game without affecting your opponent. A smile wins a lot of points because it gives the impression of confidence on your part that shakes that of the other man. Fight all the time. The harder the strain the harder you should fight, but do it easily, happily, and enjoy it.
Match play, where both men are in the same class as tennis players, resolves itself into a battle of wits and nerve. The man who uses the first and retains the second is the ultimate victor.
I do not believe in a man who expects to go through a long tournament, going "all out" for every match. Conserve your strength and your finesse for the times you need them, and win your other matches decisively, but not destructively. Why should a great star discourage and dishearten a player several classes below him by crushing him, as he no doubt could? A few games a set, well earned, would be a big factor in encouraging that rising player to play in tournaments, while it would in no way injure the reputation of the star.
Never hurry your opponent by serving before he is fully set to receive. This is a favourite trick of a few unscrupulous players, yet is really an unfair advantage. Do your hurrying after the ball is in play, by running him to unexpected places in the court. Should anyone attempt to work the hurried service on you, after several attempts, proving it is intentional, let the ball go by and say "not ready." The server will shortly realize that you will take your time regardless of him, and he will slow up.