Sixty-fifth KGS Computer Go Tournament

Sunday November 7th 2010

These results also appear on an official KGS page which links to the records of all the games.


format8-round Swiss
board size19×19
time29 minutes plus 25/60s


The first round started at 16:00 UTC.

Result table



Orego12 vs WeakBot50k
Moves 11-19.

In round 1 Orego12 played WeakBot50k SGF. Orego12 did not respond when its stones were in atari, allowing WeakBot50k to capture several of them as shown to the right. I judge that at the end of the sequence shown, WeakBot50k is ahead, and Orego12's play has been poor. But soon after this, WeakBot50k had some stones caught in a ladder: the only thing it understands is capture, "if my opponent's group is in atari, capture it, if mine is in atari, pull it out". So the ladder was played out, and Orego12 won easily.

Break19 achieved a won position against IdiotBot, but then lost on time.

In round 2, ManyFaces2 beat CzechBot SGF. This was CzechBot's only loss in the tournament.

Orego12 vs CzechBot
Moves 119-141.
130, 131, 140: all tenuki

In the round 3 game between CzechBot and Orego12 SGF, CzechBot caught Orego12's stones in a ladder, as shown to the left.

I do not mention this to criticise Orego. Orego is a not a bad program, and plays some good games. But it is also clear that it suffers from some defect, which in this game caused it to lose. Probably most programs have serious bugs like this. I believe that in the short term, for most programs, bug-fixing would produce better results than development of new code.

Zen19 vs ManyFaces2
Moves 159-173.
160: tenuki
In round 4 Zen19 and ManyFaces2, the only programs still undefeated, played SGF. The sequence shown to the right was played. If this were a game between humans, I would write, "By descending at 159, Black threatened the white corner. However, White misread, and tenukied. Black killed the corner. Move 172 is inexplicable." But as these are two MC-based programs, "misread" is not the right word. Even so, move 172 is still hard to explain. Maybe Zen19 calculated "if Black does not capture, this move will work really well". Or maybe this is evidence of a bug.

ManyFaces2 won the game, to become the only undefeated player.

In round 5, AyaMC played ManyFaces2 SGF. AyaMC won a semeai in the centre of the board, and the game: this was ManyFaces2's only loss.

Also in round 5, Zen19 played CzechBot SGF. The last move of any value was 187, which left CzechBot 3½ points ahead. But the game continued for another 215 moves, with CzechBot making a futile attempt to live inside Zen19's territory, which Zen19 answered only as necessary, passing when no response was necessary. Some kibitzers were confused by what was happening. Those who trusted the counts made by the KGS "ScoreEst" function were most confused: ScoreEst counts prisoners twice when Chinese rules are in use. By the end, CzechBot was still 1½ points ahead, giving Zen19 its second defeat of the day.

In round 6, break was missing, giving PNUGo a win by default.

In round 7, break was still missing, giving Orego12 a win by default.

In round 8 break reappeared, and played its game against IdiotBot.

Also in round 8, PueGo timed out on the last of its 25 moves in its game against WeakBot50k SGF. It seems that 25 moves in 60 seconds is not quite enough, netlag can exceed three seconds a move.


Details of processor numbers, power, etc.

Aya, running on 6 cores of an i980X 3.3GHz
break, probably running on a single processor Intel(R) Celeron(R), 1.7Ghz
MoGo, running on an 8-thread i7 920, 6GiB RAM
running on Linux, 2GiB RAM, Intel(R) Celeron(R) M CPU 530 @ 1.73GHz
Many Faces of Go, running on four cores of a 12-core Xeon for the first round, and all 12 cores of a 12-core Xeon for the rest of the tournament.
Orego, running on one of the five nodes a custom Linux cluster build by PSSC Labs: AMD Six Core Dual Opteron 2427 2.2 GHz (12 cores total), 8 GB RAM, Centos Linux
pachi, running on an 8-thread i7 920, 6GiB RAM
Fuego, running on an 8-thread i7 920, 6GiB RAM
GNU Go, running on a Core2 Duo E7200 2.53GHz
running on Linux, 8GiB RAM, AMD Athlon(tm) 64 X2 Dual Core Processor 4000+
valkyria, running on a i7-860 4 Core processor at 2.80 Ghz.
running on Linux, 2GiB RAM, Intel(R) Celeron(R) M CPU 530 @ 1.73GHz
Zen, running on a Mac Pro 8 core, Xeon 2.26GHz