good sport

is a thing you can only prove you are by losing.

The only way to prove that you're a good sport is to lose. Ernie Banks

 involves letting people teach you a lot of things you already know.

IF you wish to be a good sport you must let people teach you a lot of things you already know.

is a man whose soul is equipped with automatic lubrication.

lubrication

is one who, when they win, says nothing, and when they lose, says even less.

is one who always imitates the behavior of the winners when they lose.