Turochamp Turned Chess Judgment Into Rules
Turochamp was not a machine that understood chess in a human sense. It was a procedure for comparing moves: examine legal options, assign each resulting position a score using chess-related criteria, and choose the move that scored best. Such criteria are called heuristics—practical rules of thumb that help make a difficult decision without calculating every possibility.
That approach was a major design choice. Chess branches quickly: after each move, both players have many replies, and the possibilities multiply. Turochamp’s rules offered a way to make a choice without exploring the game tree as deeply as modern chess engines do. The aim was not to reproduce a player’s intuition, but to make that intuition operational: express useful judgments as steps a procedure could follow.
The Computer Was Turing
The procedure existed on paper, but no available computer could run it. So Turing acted as the processor, carrying out its calculations by hand. For each turn, he had to follow the rules and compare candidate moves rather than simply play the move he personally preferred. That made a single decision laborious—roughly half an hour—and exposed the gap between a program’s design and its execution.
The experiment mattered because it showed that a chess-playing program did not have to be a physical machine to be tested. Its rules could be run by a person, one calculation at a time. Turochamp’s slow manual play was therefore both a game and a practical demonstration: a computer’s “thinking” could be specified as a sequence of operations, even before a computer was available to perform them.
