雙語暢銷書《艾倫圖靈傳》第5章:解謎接力賽(120)
Reducing the figure of thirty to a mere two for the sake of a diagram, the player (White) making a three-move look-ahead is confronted by a 'tree' such as:
Current position, W to play
當前局面，白方走棋Position resulting from the 2 possible W moves
白方的2種着法會導致的局面
Position resulting from the possible replies
黑方的着法會導致的局面Position resulting from the possible W replies.
白方的着法會導致的局面These positions are evaluated by scoring.
對這些局面用分數進行評估A human playing White might reason that it would be good to reach position E, but Black will not be so obliging, and will respond to move B by reply F.
白方可能會認爲，到達E是最理想的，但黑方不會這麼樂於助人，如果白方走到B，那麼他就會迴應F。A second best, for White, would be position D, but again it must be assumed that Black will play C to prevent this.
對白方而言，第二好的選擇是D，但同樣可以想見，黑方會走到C來避免D。Of the two evils, positions C and F, C is the lesser one, since at least it guarantees for White a position of value 27. So White plays move A.
在這兩個不幸中，C和F局面相比，C的危險性更小一些，因爲它能使白方保證至少達到價值爲27的局面。因此白方會進行A移動。A 'machine' could simulate this train of thought by a method of 'backing up' the tree.
機器可以通過推導這棵樹，來模擬這一系列想法。Having worked out all the scores for three moves ahead, it would then label the intermediate positions on a minimax basis.
對三步之後的各種局面進行評估之後，根據最大值最小化的思想，對中間各層的局面進行標示。It would assign 27 to C, 45 to D, 81 to E, 16 to F (the best in each case), then 27 to A, 16 to B (the worst in each case), and finally select move A for White.
它會將C標爲27, D標爲45, E標爲81, F標爲16（每個下面的最好局面），然後將A標爲27, B標爲16（每個下面的最壞局面）。
