Erik van der Werf wrote: > On Dec 10, 2007 6:07 PM, Álvaro Begué <[EMAIL PROTECTED]> wrote: > >> It looks like even under non-superko rules, something special happens if a >> position is repeated, which means that a program should know the entire >> history of the game, or it may accidentally repeat a previous position, even >> if it is winning the game by a large margin. >> > > Yes, but my point was that this special thing does not necessarily > have to happen directly. > > If both sides have played the full cycle at least once then they have > had every opportunity needed for analysis and for playing elsewhere. > If neither side chooses to abandon the cycle (and look-ahead can show > there is a cycle anywhere in the cycle!) then there is no need to play > forever and the server (referee) can simply decide the result based on > a long-cycle analysis. > > This is exactly how it's used in chess. In both games a repetition can be "game changing", leading to a draw in chess or an illegal move (or loss) in Go. But when use to record positions it is assumed that nothing relevant is behind you. Even if it is, the game isn't fundamentally changed. In chess you are given 3 repeats before a draw can be claimed so one could just view this a a couple more chances. Same in Go.
There is an important difference in chess. In chess, it's not illegal to repeat the same position even hundreds of times. A draw MUST be claimed by the player who is about to repeat the position. If he fails to claim the draw, the opponent may have the opportunity to claim the draw (when it is his move) but neither player is absolutely obligated to claim it. In Go however, even if the fundamental game is unchanged you may be playing illegal moves if you are not aware of the superko situation. Such a system is perfectly fine for recording interesting positions such as test suites and such. - Don > Erik > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
