This is not an official KGS page.

Fifth KGS Computer Go Tournament

Sunday August 14th, 2005

These results also appear on official KGS pages: Formal Division, Open Division which link to all the game records.


19x19 board
Chinese rules, komi 7½
28 minutes each absolute time


Round Robin


The first round started at 08:00 GMT for the Formal and 08:10 for the Open division, subsequent rounds started at one-hour intervals.


The tournament was again held in two divisions, Formal and Open, with more restrictive entry conditions for the Formal division. Essentially, an entrant to the Formal division must not contain move-generating code used by any other such entrant, and its author's real identity must be known. A program may enter both divisions simultaneously (though it will have to use different names for each).

Formal Division

1stGNU3 wins
2ndAyaBot2 wins
3rdDariush1 win
4thgonzoBot0 wins

Open Division

1stGnuGo25 wins
2ndLibertyBot4 wins
3rdgonzoBot22 wins
5thIdiotBot1 win

The winner of the Formal division was GNU, a recent version of GNU Go.

The winner of the Open division was GnuGo2, an old version of GNU Go. Congratulations to both GNU Gos on their undefeated wins.

The "real" names of the bots listed above, and of their programmers, are listed here: programs which have registered for KGS Computer Go Tournaments.

Description, Formal division

In round 1, AyaBot outplayed Dariush to win by 49½ points. GNU easily beat gonzoBot. GonzoBot, in both its versions and all its games, had a problem with the game end, and failed to agree on a score, so the game was aborted. As a consequence, it is shown on the KGS web site as "forfeited", and in its KGS games list as escaped; so it is not available. Viking4 failed to show up, and was assigned a bye.

In round 2, GNU beat Dariush by 7½ points. AyaBot beat gonzoBot, which had its usual problem. Viking4 failed to show up again, and was assigned another bye.

In round 3, the game between GNU and AyaBot would decide the winner of the tournament. Ayabot did well at the beginning, killing a corner. But GNU made, and maintained, a large central moyo, and won by 40½ points. Dariush beat gonzoBot, which had its usual problem. Viking4 failed to show up again, and was assigned a third bye.

Each player which had showed up had now played each of the others, so one might expect the tournament to be over. However, the absent viking4 had not played a game yet, and this, presumably, was why the scheduler created a fourth round. Viking4 was still absent, so it got a bye. Each of the other four bots also got a bye.

Now, viking4 was guilty of four no-shows, and was expelled from the tournament, as this was configured to allow only three no-shows each. However, the scheduler did not consider this sufficient to end the tournament. It scheduled a fifth round, with a bye for each of the four surviving bots. Of these, Ayabot did not show up (it had gone home an hour before). These two all-bye rounds seem to have had no effect on the results.

Description, Open division

In round 1, LibertyBot had no trouble in beating SimpleBot. SimpleBot is handicapped by its habit of playing out ladders that don't work because the stones that it is laddering have a few spare liberties; it lost this game by 213½ points. GnuGo2 had no trouble beating gonzoBot2, which as usual did have trouble with the game end. Wbot beat IdiotBot by 322½ points, but had an unusual argument at the game end. Instead of the usual kind of argument, which goes "Your stones are dead" "no mine are alive" "no yours are dead" "no mine are alive" (repeat ad infinitum), this one went "your stones are alive " "no mine are dead" etc.. In fact IdiotBot was right in claiming that its own one-eyed group was dead, but Wbot could not see that it could kill it. Wbot's owner resolved the argument by logging in as it, causing it to lose by forfeit, and this game is shown as a win to IdiotBot on the KGS web site, but as a win to Wbot on this page.

In round 2 LibertyBot killed all of IdiotBot's stones. GonzoBot2 easily beat SimpleBot, winning by 127½ points. GnuGo2 beat Wbot, which again had an argument at the game end, denying that it could kill things which it could kill.

In round 3 GnuGo2 beat SimpleBot easily, winning by 269½ points. Wbot had its usual anti-argument, this time with LibertyBot, and again the tournament organiser had to step in and assign the result, a win to LibertyBot. GonzoBot2 killed all of IdiotBot's stones, and as usual insisted on playing on while any of its territories had more than two points of territory. Normally this bahaviour is harmless, but in this game it had a whole board to fill up, and lost on time while planning move 682.

In round 4 GnuGo2 beat IdiotBot by 336½ points. LibertyBot beat gonzoBot2, by a margin which is not not recorded because of gonzo's game end problem. Wbot beat SimpleBot in a game which is also unrecorded.

In round 5 gonzoBot2 and Wbot had an interesting game. GonzoBot2 made a secure group along the lower edge, while Wbot made most of the board into its moyo. As gonzo never dares to invade this looked like a winning strategy for Wbot. But gonzo nibbled piecemeal at the frontier, until it was ahead by 154½ points. Somehow, these two programs, which are normally troublesome at the game end, managed to agree on the result. In the game that decided first place, GnuGo2 played rather better than LibertyBot, for a winning margin of 88½. IdiotBot killed most of SimpleBot's stones, for a margin of 185½


There is something odd about the way the number of rounds in a Round Robin is decided. I think I understand whay there was a fourth round in the Formal division; but not a fifth round.

Wbot and gonzoBot have trouble with the game end.

Don't log in using your bot's account during a tournament. If you do, the system will assume you are cheating and assign it a loss. If you need a result assigned in a game, ask the tournament organiser. I don't think it helps to log in as your bot; when two bots get stuck in an endless argument about the status of some stones, it seems to be necessary to have an admin (thanks, glue) kill the game anyway, and once the game is killed, I assume the bots have the sense to stop trying to argue in it.