X.
Amongst good players, it is considered to be as much an indispensable condition of the game, that a piece once touched must be moved, as that the queen is not allowed to have the knight's, or a rook the bishop's move.
XI.
Some persons, when they are playing with a stranger who entreats to be allowed to take back a move, let him do so the first time: then, almost immediately afterwards, they put their own queen en prise; and when the mistake is politely pointed out to them, they say that they never take back a move, but that they are ready to begin another game.
XII.
Do not be alarmed about the state of your adversary's health, when, after losing two or three games, he complains of having a bad head-ache, or of feeling very unwell. If he should win the next game, you will probably hear no more of this.
XIII.
Never (if you can avoid it) lose a game to a person who rarely wins when he plays with you. If you do so, you may afterwards find that this one game has been talked of to all his friends, although he may have forgotten to mention ninety-nine others which had a different result. Chess players have a very retentive memory with regard to the games which they win.
XIV.
If, therefore, any one should tell you that on a certain day last week he won a game from one of your friends, it may be as well to ask how many other games were played on the same day.