Magnus, It seems I didn't go deep enough into the game. I assumed that after quite a few moves we could reach some tentative conclusion that was likely to be correct, but it looks like there is a good chance it is not correct!
What I should have done was to take the time to mini-max the statistics. What I'm doing is more tedious than just writing a program to do it for me. I found another line of play too. See my responses to your stuff below: On Tue, 2008-09-30 at 22:09 +0200, Magnus Persson wrote: > I have been trying to see what Valkyria does. But it is a little > unstable when it reads deep at 6x6. It should not be a problem for > Valkyria but I have not had any time to search for the bug. > > Anyway the 2.5 komi black should lose if Don is right. So I have the > following very cute complete game sequence: > > bC4 wD3 bC3 wD4 bD5 wE5 bD2 wE2 ... > > The beginning is very natural, and although I did not check carefully > all what Don reported but I think there is agreement that this is a > strong seqence for both colors. > > ... bE3 wE4 bE1 wF3!!!... In my data from Leela, F3 is looked at 100 times here and Leela considers it the best move too: b w b w b w b w b w b w C3 D4 C4 D3 D5 E5 D2 E2 E3 E4 E1 F3 24 out of 110 = 21.818 percent C3 D4 C4 D3 D5 E5 D2 E2 E3 E4 E1 C5 6 out of 18 = 33.333 percent > > Normally wF2 is played in the corner. But with wF3 white has the > option to play aggresively with wF1 which usually is a bad idea > because the ko fight risk to much. But on a small board things are not > normal... > > ... bC1 wC5 bB5 wD6 bB6 wF1!... It's interesting that Leela considers C1 a losing move! However, C2 actually wins more than half the time in the games. (Just because Leela doesn't like bC1 doesn't mean it isn't correct however.) I have further analysis that shows that C2 works: b w b w b w b w b w b w After C3 D4 C4 D3 D5 E5 D2 E2 E3 E4 E1 F3 C1 0 out of 10 = 0.000 percent F2 0 out of 5 = 0.000 percent B2 0 out of 18 = 0.000 percent C2 24 out of 44 = 54.545 percent D1 0 out of 33 = 0.000 percent I had to follow this analysis pretty deep as the next several moves appear forced from Leela point of view. There were a few games thrown away where black played something stupid, so I'm not including them. I eventually get this which I will call Leela's principal variation: b w b w b w b w b w b w After C3 D4 C4 D3 D5 E5 D2 E2 E3 E4 E1 F3 b w b w b w b w C2 C5 B5 D6 B6 F1 F2 C6 24/35 = 68.571 percent I don't know about your line, but it appears that maybe black DOES win with this line (and perhaps your line too) unless we can find a white improvement. So it may very well be that we should test 3.5 komi! It appears that black had the choices - so unless we can find a white improvement I am inclined to believe that 3.5 komi is closer to the truth. The lesson here seems to be that even 6x6 is deep for very strong computer programs. Even in 6x6 after getting out 20 moves Leela is not sure this is a win for black. (I'm not sure either, I am just assuming that 24/35 = 68.571 percent represents a win for black.) - Don > > white starts a ko. If white first plays wC6 bF1 wins the game right away. > > ...bF2 wC6 bB4!!!!! > > if I understand this move it is a truly cool move. If black plays the > larg ko at E3 as most people would instinctively do including myself > white cuts at B4 and get a lot of kothreats and wins the game. With > bB4 white has no ko threats. > > ...wF1 bE6 wF6 bF2 wE3 bD1 wF1 bF5 wF4 bF2 wPass bF1 B+3.5 > > So komi should be larger unless there are a mistakes by white in this > sequence. > > Valkyria should have the credit for all strong moves here but they are > not always found, so this analysis is also shaky. At short time > controls I do not think any existing MC programs will get these things > right. > > Even if it is wrong I found some of the moves really fascinating. The > search behavior of Valkyria jumps up and down between 25-75% all the > time as these moves are found. If it had been more stable maybe I > could just let it run for a long time and find out stuff more or less > for sure. But I hope this sequence adds some understanding at least. > > -Magnus > > > Quoting Don Dailey <[EMAIL PROTECTED]>: > > > I would be very interested in various opinions on this. Is the correct > > komi for 6x6 (under CGOS type rules) 2.0? > > > > Especially would I like to see some strong players review my (actually > > Leela's) analysis and weight in on this. > > > > Do you think we can say with relatively high confidence that 2.0 is the > > correct komi for 6x6 go? > > _______________________________________________ > computer-go mailing list > email@example.com > http://www.computer-go.org/mailman/listinfo/computer-go/
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