Re: [Computer-go] Komi for 13x13
Here's an intuitive argument for why I believe 7.5 komi is too high on any of the larger boards. On very small (square odd-surface) boards there is no room for White to live (Black takes all points). Past a certain point (5x5), Black can no longer control the full board, so White also starts to take some points. Initially there is not much room left for White, so the perfect komi remains a bit high (e.g., 9 for 7x7), but as the size increases the White move values start to approach those of Black and I expect the advantage of the initiative to decrease to a constant (probably 7 or 5 points). Since we have reasonable indications that the first player score on 9x9 is no higher than 7, and because it is unlikely to increase with size, the main question is if it remains at 7, or if it drops down further (e.g., to 5). (even values such as 6 are much less likely on odd-surface boards with area scoring). Of course one could still argue that 7 is correct, and we just add 0.5 to prevent ties, but then I'd rather subtract 0.5 and go for a komi of 6.5 because I prefer the small advantage to go to the first player. Best, Erik BTW Nick, is there any chance that you will at some point run a kgs tournament with territory scoring? I'm still hoping that one day we will play Japanese rules with 6.5 komi. (Regardless of the komi, I think the more fine-grained territory scores would make the games more interesting, especially on 9x9.) On Tue, Aug 5, 2014 at 11:10 AM, Nick Wedd n...@maproom.co.uk wrote: In January 2011, I took a poll on what komi to use for 9x9 bot tournaments on KGS. There was a majority in favour of changing from 7.5 to 7. During Sunday's 13x13 KGS bot tour, someone suggested also changing the 13x13 komi from 7.5 to 7. The main argument for changing must be that 7.5 favours White. So here are the statistics from recent KGS 13x13 bot tournaments: White Black wins wins 2014 August 13 9 April 36 27 2103 December12 18 April 28 20 TOTALS 89 74 I am inclined to think there is not a convincing reason to change. But I will welcome persuasion; or better, more statistics. Nick -- Nick Wedd n...@maproom.co.uk ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
Re: [Computer-go] Komi for 13x13
On 05/08/2014 12:25, Erik van der Werf wrote: Here's an intuitive argument for why I believe 7.5 komi is too high on any of the larger boards. On very small (square odd-surface) boards there is no room for White to live (Black takes all points). Past a certain point (5x5), Black can no longer control the full board, so White also starts to take some points. Initially there is not much room left for White, so the perfect komi remains a bit high (e.g., 9 for 7x7), but as the size increases the White move values start to approach those of Black and I expect the advantage of the initiative to decrease to a constant (probably 7 or 5 points). Since we have reasonable indications that the first player score on 9x9 is no higher than 7, and because it is unlikely to increase with size, the main question is if it remains at 7, or if it drops down further (e.g., to 5). (even values such as 6 are much less likely on odd-surface boards with area scoring). Of course one could still argue that 7 is correct, and we just add 0.5 to prevent ties, but then I'd rather subtract 0.5 and go for a komi of 6.5 because I prefer the small advantage to go to the first player. I find your logic convincing. We'll see if others do. But even if they do, is that a sufficient reason for changing the komi in events that I run? With 9x9, getting the komi slightly wrong biases the results markedly, and so should be avoided. With 19x19, getting the komi slightly wrong makes much less difference to the results of games, and it may be better to use slightly wrong komi than to inconvenience those bot authors who have not persuaded their bots to understand integer komi and the possibility of jigo. Best, Erik BTW Nick, is there any chance that you will at some point run a kgs tournament with territory scoring? I'm still hoping that one day we will play Japanese rules with 6.5 komi. (Regardless of the komi, I think the more fine-grained territory scores would make the games more interesting, especially on 9x9.) I use area scoring because, with the KGS clean-up procedure, it allows almost all games to end without my intervention. KGS does not offer a similar mechanism for what it calls Japanese rules. I do not want to be required to apply my rules knowledge and counting ability in a game which ends with the players disputing the status of a bent four in the corner. Nick On Tue, Aug 5, 2014 at 11:10 AM, Nick Wedd n...@maproom.co.uk wrote: In January 2011, I took a poll on what komi to use for 9x9 bot tournaments on KGS. There was a majority in favour of changing from 7.5 to 7. During Sunday's 13x13 KGS bot tour, someone suggested also changing the 13x13 komi from 7.5 to 7. The main argument for changing must be that 7.5 favours White. So here are the statistics from recent KGS 13x13 bot tournaments: White Black wins wins 2014 August 13 9 April 36 27 2103 December12 18 April 28 20 TOTALS 89 74 I am inclined to think there is not a convincing reason to change. But I will welcome persuasion; or better, more statistics. Nick -- Nick Wedd n...@maproom.co.uk ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go -- Nick Wedd n...@maproom.co.uk ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
Re: [Computer-go] Komi for 13x13
On Tue, Aug 5, 2014 at 2:20 PM, Nick Wedd n...@maproom.co.uk wrote: On 05/08/2014 12:25, Erik van der Werf wrote: Here's an intuitive argument for why I believe 7.5 komi is too high on any of the larger boards. On very small (square odd-surface) boards there is no room for White to live (Black takes all points). Past a certain point (5x5), Black can no longer control the full board, so White also starts to take some points. Initially there is not much room left for White, so the perfect komi remains a bit high (e.g., 9 for 7x7), but as the size increases the White move values start to approach those of Black and I expect the advantage of the initiative to decrease to a constant (probably 7 or 5 points). Since we have reasonable indications that the first player score on 9x9 is no higher than 7, and because it is unlikely to increase with size, the main question is if it remains at 7, or if it drops down further (e.g., to 5). (even values such as 6 are much less likely on odd-surface boards with area scoring). Of course one could still argue that 7 is correct, and we just add 0.5 to prevent ties, but then I'd rather subtract 0.5 and go for a komi of 6.5 because I prefer the small advantage to go to the first player. I find your logic convincing. We'll see if others do. But even if they do, is that a sufficient reason for changing the komi in events that I run? With 9x9, getting the komi slightly wrong biases the results markedly, and so should be avoided. With 19x19, getting the komi slightly wrong makes much less difference to the results of games, and it may be better to use slightly wrong komi than to inconvenience those bot authors who have not persuaded their bots to understand integer komi and the possibility of jigo. Sure, I understand. But on the other hand, does it really matter if occasionally some bot doesn't get jigo? Also, they have to get this right anyway for the 9x9 tournaments. I think the choice should be made based on weighting the advantage of having no ties (always a winner, easy pairing) against the amount of bias in the starting condition (so it also matters if, e.g., you run single or double round robin). Weighting the two, I prefer fractional komi for 19x19 and integer komi for 9x9. For 13x13 I'm not sure, but I'm tempted to go for integer komi as well. In any case, if you don't want integer komi you could still switch to 6.5. It might be interesting to see if that turns it into hinting at a slight advantage for Black. BTW Nick, is there any chance that you will at some point run a kgs tournament with territory scoring? I'm still hoping that one day we will play Japanese rules with 6.5 komi. (Regardless of the komi, I think the more fine-grained territory scores would make the games more interesting, especially on 9x9.) I use area scoring because, with the KGS clean-up procedure, it allows almost all games to end without my intervention. KGS does not offer a similar mechanism for what it calls Japanese rules. I do not want to be required to apply my rules knowledge and counting ability in a game which ends with the players disputing the status of a bent four in the corner. Ah yes, that makes sense. Implementing a proper cleanup procedure for territory scoring is not difficult. Of course a practical implementation might differ slightly from the official Japanese rules, but then again KGS didn't really implement the official Chinese rules either... Erik ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
Re: [Computer-go] Komi for 13x13
On 05/08/2014 14:05, Erik van der Werf wrote: On Tue, Aug 5, 2014 at 2:20 PM, Nick Wedd n...@maproom.co.uk wrote: On 05/08/2014 12:25, Erik van der Werf wrote: Here's an intuitive argument for why I believe 7.5 komi is too high on any of the larger boards. On very small (square odd-surface) boards there is no room for White to live (Black takes all points). Past a certain point (5x5), Black can no longer control the full board, so White also starts to take some points. Initially there is not much room left for White, so the perfect komi remains a bit high (e.g., 9 for 7x7), but as the size increases the White move values start to approach those of Black and I expect the advantage of the initiative to decrease to a constant (probably 7 or 5 points). Since we have reasonable indications that the first player score on 9x9 is no higher than 7, and because it is unlikely to increase with size, the main question is if it remains at 7, or if it drops down further (e.g., to 5). (even values such as 6 are much less likely on odd-surface boards with area scoring). Of course one could still argue that 7 is correct, and we just add 0.5 to prevent ties, but then I'd rather subtract 0.5 and go for a komi of 6.5 because I prefer the small advantage to go to the first player. I find your logic convincing. We'll see if others do. But even if they do, is that a sufficient reason for changing the komi in events that I run? With 9x9, getting the komi slightly wrong biases the results markedly, and so should be avoided. With 19x19, getting the komi slightly wrong makes much less difference to the results of games, and it may be better to use slightly wrong komi than to inconvenience those bot authors who have not persuaded their bots to understand integer komi and the possibility of jigo. Sure, I understand. But on the other hand, does it really matter if occasionally some bot doesn't get jigo? Also, they have to get this right anyway for the 9x9 tournaments. I think the choice should be made based on weighting the advantage of having no ties (always a winner, easy pairing) against the amount of bias in the starting condition (so it also matters if, e.g., you run single or double round robin). Weighting the two, I prefer fractional komi for 19x19 and integer komi for 9x9. For 13x13 I'm not sure, but I'm tempted to go for integer komi as well. In any case, if you don't want integer komi you could still switch to 6.5. It might be interesting to see if that turns it into hinting at a slight advantage for Black. BTW Nick, is there any chance that you will at some point run a kgs tournament with territory scoring? I'm still hoping that one day we will play Japanese rules with 6.5 komi. (Regardless of the komi, I think the more fine-grained territory scores would make the games more interesting, especially on 9x9.) I use area scoring because, with the KGS clean-up procedure, it allows almost all games to end without my intervention. KGS does not offer a similar mechanism for what it calls Japanese rules. I do not want to be required to apply my rules knowledge and counting ability in a game which ends with the players disputing the status of a bent four in the corner. Ah yes, that makes sense. Implementing a proper cleanup procedure for territory scoring is not difficult. Of course a practical implementation might differ slightly from the official Japanese rules, but then again KGS didn't really implement the official Chinese rules either... The issue is not that it's difficult, it's that wms will not have time to do it. If he ever does have some time to work on KGS, there are many higher priorities, including getting the stone-click in the human client to work without a messy bodge, and getting the authentication for the human client to work for users who install the latest release of Java. Nick -- Nick Wedd n...@maproom.co.uk ___ Computer-go mailing list Computer-go@dvandva.org http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
