[gnugo-devel] Eighth KGS tournament

[Gunnar Farnebäck]

GNU played in the eighth KGS tournament yesterday, as readers of the
computer-go list may already have noticed. GNU placed second in the
formal division and here's a summary of the games:

Round 1: Narrow win by 0.5 against AyaBot. GNU Go made many mistakes
and fell behind when a group died, but Aya spent an extra move to kill
the dead group and GNU Go managed to get ahead in the late endgame.

Round 2: Win by resignation against viking5. Viking made an early
mistake with G2 and then GNU Go solidly kept ahead. Strangely enough,
both GNU Go and Viking thought they were behind and white C3 was a
sign of desperation. Viking made another mistake with F5, which led to
the loss of the upper right corner and while trying to get away the
position collapsed completely, forcing Viking to resign.

Round 3: Quick (game finished in 85 seconds!) win by 30.5 against
ExBot. C5 may have been questionable, otherwise solid play.

Round 4: Clear loss by 13.5 against Dar51. GNU Go as white fell behind
early in the game, lost one group and never got back into the game.

Round 5: Win by 7.5 against indigoBot after a wild game. White gave
away a stone with H2, but when trying to catch it GNU chose the risky
and complicated F2 over the simple F3, initiating a huge exchange
where black and white almost completely switched corners. In the
endgame GNU Go got ahead and won easily.

Round 6: Big loss by 34.5 against CrazyStone. This loss was really
unnecessary. White made a bad second move at F8 but GNU Go answered
with the nonsensical move (cap?) at D8. Then in response to E7 it
played the terrible B8. White was ahead but invited black back into
the game and GNU Go could have secured it with D5 instead of the
greedy G4. After a number of questionable black moves, white managed
to get life in the lower left corner or alternatively a big semeai.
GNU Go chose the latter but managed to lose it outright.

Round 7: Clear win by 19.5 against tlsBot but E7 should have been at
E4. After black C3 the game was easy.

Round 8: GNU Go swept the board with firstgo. GNU Go made a bad
mistake when it played E2, but firstgo failed to take any immediate
advantage of it. Then GNU Go blundered again by playing E8 instead of
saving the cutting stone D5. Although white did catch D5, it
subsequently played too badly to have any chance and finally lost all
its stones and the game by 73.5 points.

This summary can also be found on the wiki at
http://trac.gnugo.org/gnugo/wiki/TournamentKGS8.

Game records are already in CVS in the
regression/games/kgs/tournament8 directory. I'm preparing testcases
but can someone tell me exactly where the Dariush game (round 4,
GNU-Dar51.sgf) went wrong? I'm suspicious about B4 but it's from the
fuseki database.

/Gunnar