On Fri, Oct 3, 2008 at 2:33 PM, Don Dailey <[EMAIL PROTECTED]> wrote: > I had heard somewhere that there are some who believe 8.0 is the right > komi for 9x9 Chinese. I personally believed for a long time it was 7.0 > based on statistical data of games. However that can be misleading.
Do you understand why even numbers are very unlikely? It's rather trivial, but somehow many people seem to miss it... On 9x9 the board we know that all intersections are either Black (B), White (W), or Neutral (N): B + W + N = 81 Without seki: W = 81 - B (no neutral intersections in the final position, so N = 0) Score = B - (W + komi) = 2B - (81+komi) Consequently: with 5.5 komi Black needs 44 points to win, with 6.0 komi Black needs 44 points to win, with 6.5 komi Black needs 44 points to win, with 7.0 komi Black needs 44 points to tie, with 7.5 komi Black needs 45 points to win, with 8.0 komi Black needs 45 points to win, with 8.5 komi Black needs 45 points to win, with 9.0 komi Black needs 45 points to tie At high levels on 9x9 it appears to be extremely difficult for Black to get 45 points. With seki: N = even For the common type of seki, where the stones living in seki share two liberties, the perfect komi is again an odd number; results are therefore consistent with the numbers above (without seki). N = odd Only if optimal play inevitably leads to a seki with an odd number of neutral intersections the perfect komi becomes an even number (in which case 7.5 might make sense). However, given what is known from professional level 9x9 games this seems unlikely. If there really are persons that believe that the perfect komi on 9x9 should be 8.0 then I would very much like to see a game record of such a game... I'm sure some top 9x9 programs will have fun trying to tear it apart :-) Erik _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
