Tennis is a game that requires players to have good ethics. Outside of the very highest levels of the sport, players are required to call their opponent's shots in or out, as well as keep up with the score.
Players are required to give the opponent the benefit of the doubt if they are not sure whether a shot was in or out. "When in doubt, call it out" is not in the tennis code of ethics, and sportsmanship in tennis is extremely important. If both players are able to tell their opponent "good shot" or clap and say "too good" when credit is due, this can make the level of play rise and help the players execute at a very high level. If only one player is following the sportsmanship challenge, it may initially seem that the opponent who is not doing so has an advantage.
However, as the match progresses, the player who is calling all the close balls in their own favor will tend to be more on edge, and the player exhibiting the "fair play" attitude will likely be more even with their emotions. Obviously, if one player perceives the opponent as a cheater and gets upset due to the numerous bad calls, this can destroy the advantage held by exhibiting good sportsmanship.
In addition, if you are constantly reacting negatively to your errors, displaying a "moping" attitude, and giving your opponent very little or no credit, it is very unlikely you will be able to focus well enough to play at a high level. Good sportsmanship can give you a relaxed demeanor and will actually help you play better and win more matches.
Steve Annacone, USPTA Elite Pro, is the Director of Annacone Tennis (http://www.annaconetennis.com) and MyHamptonsPro based in Sag Harbor, NY (http://www. myhamptonspro.com) and Tennis Professional at Ventana Canyon Golf and Racquet Club in Tucson, AZ. For details on lessons, clinics, or coaching, contact Steve at email@example.com or call 865-300-7323