"No, John."
Sherlock's exasperated voice cut through John's haze of concentration yet again. "You can't go there."
"Whyever not?" John asked wearily, removing his hand from his rook.
"Because then your castle is vulnerable to my bishop," Sherlock explained, pointing.
"Sherlock," John said severely. "It's no fun when you analyze every move I make. Making mistakes is part of the activity- but of course, as you never make mistakes, chess is probably not your game."
"You're correct, John."
With one swift motion, Sherlock overturned the chessboard. Pieces flew everywhere, and Sherlock sat back, satisfied.
"We'll play tiddlywinks instead," he decided.