342 | 31 COmPUTER CHESS—THE fIRST mOmENTS
approach, and Prinz wrote a brute-force program. This examined all the possible moves until
one was found that did the job. The program ran on the Manchester University Ferranti com-
puter in November 1951. It was a significant moment, the Big Bang of computer chess. Prinz
published details in his classic article ‘Robot chess’.^45
Prinz’s program computed a White move that would lead to mate at the next move, no matter
how Black moved. Prinz fed in on punched paper tape the board position that the computer was
to examine (see Game 3, Fig. 31.3 and Fig. 27.1). He recollected that the computer ‘took about
15 minutes’ to produce the winning move.^46
It might be thought that this numbingly slow performance, and on such a simple chess prob-
lem, showed the impracticability of implementing Turochamp Mark 2 on the Ferranti. But
this doesn’t follow at all. For one thing, the brute-force approach is essentially slow: in order
to reach mate in the above very simple example, Prinz’s program tried out approximately 450
moves.^47 Moreover, a considerable proportion of the 15 minutes of computing time was used
up by wasteful transfers between the Williams tube memory and the slower magnetic drum
memory.^48 More effective use of the high-speed tube memory would have speeded the program
up. With some fancy coding, Turing could probably have made Prinz’s program run much
faster. He took little interest, though—he knew there was no future in brute-force alone.
Prinz’s program was a short-lived wonder. ‘After establishing that it worked, it was never
used again’, Prinz related. He explained:^49
The number of machine users increased so much that there was not enough time left for fri-
volities. Besides, any chess problem even slightly more complicated than the one I used would
probably have taken hours.
Nevertheless the significance of what Prinz had done was akin to the Wright brothers’ first short
flight. He had shown that computers were not just high-speed number crunchers. A computer
had played chess.figure 31.3 Game 3: the first chess
ever played by a computer. The computer
forced mate by moving R—R6 [Rh6].^50
‘Jonathan Bowen. Generated using ‘Jin’ by
Alexander Maryanovsky (http://www.jinchess.
com/chessboard/composer/).’