Re: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
I fixed allowing multiple suicide in playouts, but it didn't make the many wasted playouts go away on Sheppard's position. On further investivation, the problem has to do with the interaction between superko and the transposition table. Currently, Orego checks only simple ko most of the time. Superko is only checked at the top level, before playing a real move (as opposed to a move in a playout). This means that, within the transposition table, superko can lead to an actual cycle. Orego does have a max number of moves per playout, so it doesn't crash, but it does throw away such playouts. What is superko? My program keeps a list of all board-positions and then if it whants to do a move it checks if the new board-position is in the list. If so, it throws that move away. Are there other checks I need to do as well? Folkert van Heusden -- Feeling generous? - http://www.vanheusden.com/wishlist.php -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
In message 20090807092625.gj15...@vanheusden.com, Folkert van Heusden folk...@vanheusden.com writes What is superko? My program keeps a list of all board-positions and then if it whants to do a move it checks if the new board-position is in the list. If so, it throws that move away. Are there other checks I need to do as well? Superko involves repeating a previous board position. Various forms of this are forbidden by various rulesets, see http://www.britgo.org/rules/compare.html#threeKK What you are doing ensures that your program will never violate any form of the rule. Nick -- Nick Weddn...@maproom.co.uk ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
What is superko? My program keeps a list of all board-positions and then if it whants to do a move it checks if the new board-position is in the list. If so, it throws that move away. Are there other checks I need to do as well? Superko involves repeating a previous board position. Various forms of this are forbidden by various rulesets, see http://www.britgo.org/rules/compare.html#threeKK What you are doing ensures that your program will never violate any form of the rule. Not this one, does it? Restatement of the ko rule. One may not capture just one stone, if that stone was played on the previous move, and that move also captured just one stone. (from wikipedia) Folkert van Heusden -- MultiTail is a versatile tool for watching logfiles and output of commands. Filtering, coloring, merging, diff-view, etc. http://www.vanheusden.com/multitail/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
On Fri, Aug 7, 2009 at 5:51 AM, Folkert van Heusden folk...@vanheusden.comwrote: What is superko? My program keeps a list of all board-positions and then if it whants to do a move it checks if the new board-position is in the list. If so, it throws that move away. Are there other checks I need to do as well? Superko involves repeating a previous board position. Various forms of this are forbidden by various rulesets, see http://www.britgo.org/rules/compare.html#threeKK What you are doing ensures that your program will never violate any form of the rule. Ah ok! Odd is though that CGOS complains about Illegal KO attempted. Many time CGOS has been accused of calling a move illegal that wasn't - due to the KO rule. But so far it has never once been wrong when closely inspected. So I challenge you to show me a position where CGOS got this rule wrong! I'll give you a small monetary prize if you can :-)Just give the CGOS game number. Please note that the KO rule CGOS uses does NOT consider side to move. For example if the same exact board configuration repeats that has occurred previously, it is a positional superko violation regardless of which color is to move. Note that this is different than repetition in chess, where the same side must be on the move before consider the position as repeated. Also please note that when you play go there are other ways to define what a KO violation is. Players must agree to use the same rules when you sit down to play any game.CGOS uses the positional superko KO rule but it's also possible to play a game of go with the situational superko rule defined - which DOES take into consider the side to move. You can find disscussions on situational vs positional superko in the archives and on the web in other places - essentially there are some who feel the situational rule is more correct and more fundamental. I agree and I consider positional superko a slight complication (although by definition it is slighly simpler.) However, even though I feel that way, I chose positional superko for CGOS because I think it is more standard and accepted. - Don Folkert van Heusden -- Multitail es una herramienta flexible que permite visualizar los log file y seguir la ejecución de comandos. Permite filtrar, añadir colores, combinar archivos, la visualización de diferencias (diff- view), etc. http://www.vanheusden.com/multitail/ -- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com ___ 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/
Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
I fixed allowing multiple suicide in playouts, but it didn't make the many wasted playouts go away on Sheppard's position. On further investivation, the problem has to do with the interaction between superko and the transposition table. Currently, Orego checks only simple ko most of the time. Superko is only checked at the top level, before playing a real move (as opposed to a move in a playout). This means that, within the transposition table, superko can lead to an actual cycle. Orego does have a max number of moves per playout, so it doesn't crash, but it does throw away such playouts. To fix this, I plan to always check for superko violations. Is this what others are doing, or is there another way out? Peter Drake http://www.lclark.edu/~drake/ ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
RE: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation)
I check for superko during the UCT tree part of the search, but just simple ko during playouts. -Original Message- From: computer-go-boun...@computer-go.org [mailto:computer-go-boun...@computer-go.org] On Behalf Of Peter Drake Sent: Thursday, August 06, 2009 11:42 AM To: computer-go Subject: Superko vs transposition table (was Re: [computer-go] Double/Triple Ko situation) I fixed allowing multiple suicide in playouts, but it didn't make the many wasted playouts go away on Sheppard's position. On further investivation, the problem has to do with the interaction between superko and the transposition table. Currently, Orego checks only simple ko most of the time. Superko is only checked at the top level, before playing a real move (as opposed to a move in a playout). This means that, within the transposition table, superko can lead to an actual cycle. Orego does have a max number of moves per playout, so it doesn't crash, but it does throw away such playouts. To fix this, I plan to always check for superko violations. Is this what others are doing, or is there another way out? Peter Drake http://www.lclark.edu/~drake/ ___ 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/
