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Calibrating handicap Stones vs. komi
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Author:  SmoothOper [ Tue Mar 26, 2013 12:53 pm ]
Post subject:  Calibrating handicap Stones vs. komi

I wonder if anyone has ever calibrated the effects of handicap stones? I was thinking maybe by playing someone of equal strength with 3 handicaps but then expecting to win by 30+- points. Seems like it should be possible to calculate what the komi to handicap difference is similar to how they calculate the komi for even games. I suspect that at some point you could just win by standard corner invasions(assuming your opponent is a hoshi player).

Author:  snorri [ Tue Mar 26, 2013 3:39 pm ]
Post subject:  Re: Calibrating handicap Stones vs. komi

A naïve assumption is that a handicap stone is worth twice komi. It is easier to translate proper handicap than traditional handicap, as traditional handicap favors white.

So your traditional 3 stones, no komi translates to about 2.5 ranks, which each rank being twice komi. So 2.5 x 2 x 7 = 35 points.

You could start with that and see how it goes. But the reason I say it's naïve is that it depends on how well the black player uses handicap stones. I recall a Chinese pro saying that handicap stones are easier for the stronger player to neutralize, especially at higher handicaps, but there is obviously no special strategy to neutralize komi.

Also, I strongly suspect that the equivalence, in addition to being non-linear, also varies with strength. See, for example, the EGF winning statistics data. These show that at, say, EGF 8k a player still has almost a 30% chance of winning a game against a player three stones stronger. By 2d, the chance for the underdog (in this case against a 5d opponent in an even game) drops to 12.6%. Now this isn't handicap data, but my point is that if you try this yourself, you might be surprised and how many handicap games you win or lose vs. an opponent of your "same strength" and how far that handicap can be pushed.

Author:  RobertJasiek [ Tue Mar 26, 2013 8:50 pm ]
Post subject:  Re: Calibrating handicap Stones vs. komi

"Calibrated" would be an exaggeration, but I did try quite a few games against same-ranked players with territory scoring and fixed-pattern handicap 9 versus 130 komi, and this invade/kill mega-center game is close to 50% winning probability, provided the black player knows how to use the handicap well (not all 5d players know it). In 5d-5d games, higher komi lead to an imbalance.

EDIT:

130 / 9 = 14.44.

Author:  Bill Spight [ Tue Mar 26, 2013 9:30 pm ]
Post subject:  Re: Calibrating handicap Stones vs. komi

Back in the '70s I estimated the territory value of a handicap stone from pro-pro handicap games. There was a lot of variability, and I wasn't sure how sharp the play was. However, I got a value of about 13.75 points per stone through 9 stones. I was confident enough of the result to predict that Japanese komi would go up to 6.5 by 2000. Almost! ;)

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