The Rilke Gap / A Rilke-rés

Abstract A chess puzzle asks what chance Black has of winning a bet to mate on the second move against an opponent who chooses at random. The answer is not one number. If White is a person, the touch-move rule binds the hand: whoever touches a piece that can legally move must move that piece. A machine touches nothing, so the rule cannot reach it. The two opponents are therefore drawing from different things — the person from pieces, the machine from moves — and the probabilities part company: 1⁄110 ≈ 0.909 % for the person, 1579⁄159600 ≈ 0.989 % for the machine. The machine, which never hesitates, walks into the trap 8.8 % more often than the beginner who knows nothing. The same gap opens in a hand of cards with no chess in it at all. It is named for Rilke, who set the Machine that dares to feign spirit against the hesitation of the glorious hand.