Seventy-first KGS Computer Go Tournament

Sunday May 8th, 2011

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


format12-round Swiss
board size19×19
time14 minutes plus 10/30s


The first round started at 16:00 UTC.

Result table

Zen19 pachi ManyF AyaMC Czech Cyrag Orego Simpl PNUGo WeakB Idiot break
B13R W18R B11R W19R W16R B111R B12R W110R B14R W17290½ W15R B112285½ 128282Winner
2pachi2 W03R B08R
B14R W012R W17R B15R W11R B12R B11197½ B16 B19131½ B110203½ 98350
3ManyFaces1 W01R B09R W04R B112R
B12R W17F B13R B15R W16296½ B18225½ W111282½ B110F 97946
4AyaMC B06R W011R B07R W02R
B01R B14R W112R B19R B11043½ B1559½ B18111½ W13239½ 77829
5CzechBot W02R W05R B07F W11R
B111R B112R B0858½ B19 W110 B0368½ B1635½ W1459½ 77032
6Cyrago B010R B01R W03R W04R B012R W011R
W16R B1917½ W18½ W17132½ W15174½ B12183½ 67322
7Orego12 W04R W02R W05R W09R W012R B06R
B1345½ W11½ B111 B11075½ W17124½ W18F 67121
8SimpleBot B07290½ W01197½ B06296½ W01043½ W1858½ W0917½ W0345½
B04306½ W11368½ W12368½ B112353½ W15168½ 56915
9PNUGo B05R W06 W09 B010 B08½ B01½ W011 W14306½
B12353½ B13353½ B17T W112304½ 56512
10WeakBot50k W012285½ W09131½ W08225½ W0559½ W1368½ B07132½ W01075½ B01368½ W02353½
W14154½ W06 B111F 37010
11IdiotBot W010203½ B011282½ W08111½ W0635½ B05174½ B07124½ B02368½ W012353½ W03353½ B04154½
W11T B19F 2642
12break19 W010F B03239½ B0459½ W02183½ B08F B05168½ W07T B012304½ B16 W011F B01T W09F

In the table above,
   0 indicates a loss
   1 indicates a win
   J indicates jigo
   a superscript indicates the round in which a game was played
   a subscript shows how the result was determined:
      R for resignation
      T for time
      F for forfeit
      a number for the points difference after counting.
All the 0s, 1s and Js are links to the game record.

Twelve players registered. We welcomed one new player, Cyrago, by French programmer Harald Johnsen. Cyrago is derived from an old version of libego by Łukasz Lew, and also uses Mark Boon's ladder code.


WeakBot50k vs PnuGo
Moves 44-80

In round 2, WeakBot50k chased PNUGo's stones in a ladder that did not work for two reasons ‒ there was an extra liberty, and there was a ladder-breaker. PNUGo played correctly, as seen to the right, but spent a lot of time thinking about each move, using up most of its time for the game. However it was able to play fast in its remaining time, and win the game.

ManyFaces1 vs pachi2
Moves 63-67

In round 3 CzechBot got a won position against WeakBot50k, but then, with 3 seconds of main time left on its clock, started passing, allowed its opponent to capture some of its groups, and lost the game. It acted as if it was unaware of the overtime.

Also in round 3 Zen19 beat pachi2, to become the only played on three wins.

In round 4 ManyFaces1 and pachi2 fought a semeai in the top right of the board, as shown to the left. When ManyFaces1 tenukied with move 64, and again with 66, pachi2 played further moves to secure its win of the semeai. I find it hard to believe that this sequence can have been correct: if the semeai was unsettled White should not have tenukied, and if it was settled in Black's favour, Black should not have played there again. Pachi eventually won this game.

In round 7 CzechBot was missing from the server. It did not join its game with ManyFaces1, and lost on time. Its operator eventually realised that the computer it was running on had been switched off, and got it restarted in time for the next roiund.

In round 8 break19 was missing from the server. It lost all its subsequent games on time.

As in round 3, CzechBot again started passing when it had only 3 seconds of main time left, and lost the game as a result.

Cyrago beat PNUGo by half a point, having allowed its opponent to fill several dame while it filled its own territory, as is common with MC-based programs.

Players receive points for the 2011 Annual KGS Bot Championship as follows:

Many Faces of Go4


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
Cyrago, probably running on a single thread of a Q9550 @ 2.8 Ghz.
a development version of MoGo current as of 2010-10-06, 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 a 12 core Xeon; using pondering, for the first time
Orego, probably running on one of the five nodes of a custom Linux cluster built by PSSC Labs: the node has two AMD Six Core Dual Opteron 2427 2.2 GHz (12 cores total), 8 GB RAM, Centos Linux.
pachi, running on 64 unspecified 20-core platforms.
GNU Go, unspecified platform
running on one processor of a 4GiB RAM, AMD Athlon(tm) 64 X2 Dual Core Processor 4000+, shared with WeakBot50k
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