Except in a very few matches, usually with world-class....

“ Except in a very few matches, usually with world-class performers, there is a point in every match (and in some cases it's right at the beginning) when the loser decides he's going to lose. And after that, everything he does will be aimed at providing an explanation of why he will have lost. He may throw himself at the ball (so he will be able to say he's done his best against a superior opponent). He may dispute calls (so he will be able to say he's been robbed). He may swear at himself and throw his racket (so he can say it was apparent all along he wasn't in top form). His energies go not into winning but into producing an explanation, an excuse, a justification for losing. ”

C. Terry Warner

From : Bonds That Make Us Free: Healing Our Relationships