These results suggest that software advancements have improved the performance of computer chess programs by at least a factor of 4 in the last 15 years. The result, Cray Blitz, was one of the strongest chess programs in the world. Improved versions of the software running on multiprocessor Crays won the North American and World computer chess championships in later years. According to Hyatt, Crafty is itself a direct descendant of Cray Blitz. The critical position at move 28 is shown here, white to move.
Asterisks signify black pieces.
No program in existence at that time could have searched deeply enough in two or three minutes to see how disastrous this move is, or that it is possible to force a draw by playing Bxh6 instead. Just 12.18 seconds after being given this position, Crafty grasped the situation and changed its favored move from QxN to Bxh6 at a search depth of 9 plies, or half-moves. Cray Blitz's logs of the game reveal that it evaluated QxN to a depth of 6 plies and still thought the move overwhelmingly advantageous. Let's extrapolate that into the future. In general, any computation that requires 3 hours today will require only 1 second 20 years from now.