Seventy-ninth KGS Computer Go Tournament

Sunday January 15th, 2012

These results also appear on an official KGS page.


format8-round Swiss
board size19×19
time29 minutes plus 10/30s


The first round started at 08:00 UTC.

Result table

Zen19 pachi ManyF AyaMC MyGoF NiceG MCark Orego
B13R B12R W18R B11R B1497½ W15R B17R B16R 82929Winner
2pachi2 W03R
B07R W14R B11109½ W1816½ W16R W12R W15R 63017
3ManyFaces1 W02R B08R W17R
W16R B03T B11R B15R W14R 53515
4AyaMC W01R B04R B06R
W1510½ W12R B18R W13R W17R 52910
5MyGoFriend W0497½ W01109½ B0816½ W13T B0510½
B17R B16R W12R 4349
6NiceGo19N B05R B06R W01R B02R W08R W07R
B14R W13R 2352
7=MCark W07R B02R W05R B03R W06R W04R
B11R W08R 1321
Orego12 W06R B05R B04R B07R B02R B03R W01R B18R

In the table above,
   0 is a loss
   1 is a win
   J is jigo
   left superscript is the player's colour
   right superscript is the round in which the 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.

Eight players entered. None was new to these events: MCark last competed in October 2010, and NiceGo19N is a version of oakfoam.


At the start of round 1, ManyFaces1 joined its game with NiceGo19N, but did not play a move. Its operator needed to reboot it, and it eventually rejoined its game nine minutes late. It still won.

pachi2 vs Zen19
Moves 133 and 134.
pachi2 vs Zen19
Moves 214 and 215.

In round 3, pachi2 and Zen19, the only undefeated players, played each other. Pachi2 won a semeai, saving its large left-side group by killing Zen19's top left corner. In the position shown to the left, pachi2 as White is well ahead. Moreover, both players knew this: move 133 is a move typical of a Monte-Carlo program in a hopeless position, achieving nothing but strongly sente, while pachi2 stated that its "winning probability" was 65% (which normally means that its true probability of winning is over 80%).

At move 135, pachi2 had 12 minutes left, while Zen had 15½, so pachi2 should not have been under much time pressure. However, by move 213, pachi2 had only five minutes left, while Zen19 had ten minutes. It was now pachi2 that was acting as if its position were hopeless, making move 214 as shown in the diagram to the right. Pachi2 may still have been winning at this point, but it continued making poor moves, and lost the game.

Also in round 3, ManyFaces1 crashed in a totally won position, with all dame points filled, against MyGoFriend. It failed to finish the game, and lost on time.

In round 4, ManyFaces1 had been rebooted again, and started its game with Orego12 on time. ManyFaces1 won this game.

In round 6, pachi2 chased and killed NiceGo19N's stones in a simple ladder, and won the game.

In round 8, NiceGo19N chased AyaMC's stones in a ladder, despite AyaMC having a ladder-breaker. AyaMC won this game.

Annual points

Players receive points for the 2012 Annual KGS Bot Championship as follows:

Many Faces of Go3

Details of processor numbers, power, etc.

Aya, running on 6 cores of an i980X, at 3.3GHz.
Many Faces of Go, running 4 cores (8 threads) of an i7-2600.
MC_ark, running on a Core-i7 2600K 3.40GHz*4core (8 threads)
MyGoFriend, running on a 20-core system: two i7s each with 6 cores and two i7s each with 4 cores, all about 3.3 mhz.
oakfoam, running on an Intel Core i7-Processor 920 (2,66 GHz), 4 Cores, Linux in Virtualbox
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 platforms, each x86 64 bits, 32 GB ram, using 22 cores of each (total 1408 cores), giving about 1500 playouts/s/core at the beginning of a 19x19 game.
Zen, running 46 on a Mac Pro 8 core, Xeon 2.26GHz.