Eighty-second KGS Computer Go Tournament

Sunday May 6th, 2012

These results also appear on an official KGS page.


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


The first round started at 16:00 UTC.

Result table

pachi Zen19 ManyF stv AyaMC NiceG Orego MCark
B12R W18R B012R W17R W14R B19R W13R B111R B15R W110R B16R W1186½ 117363Winner
2Zen19 W02R B08R W112R
W13R W11R B110R W14R B19R B16R W111R W15R B17T 107654
3ManyFaces1 B07R B03R
W15R B112R B02R W06R W11R B18R B19R W110R B1497½ W111168½ 85926
4stv B04R W09R B01R W010R B05R W012R
B17R W18T W13R B12R W111R W1683½ 68022
5AyaMC B03R W011R B04R W09R W12R B16R W07R B08T
W112R W11R B1593½ W110214½ 67723
6NiceGo19N W05R B010R W06R B011R B01R W08R B03R B012R
W14R B17R B1258½ W1957½ 4766
7Orego12 W06R B05R W09R B010R W02R B011R B01R B04R W07R
W13 B18F W112 3630
8MCark B0186½ W07T W0497½ B011168½ B0683½ W0593½ B010214½ W0258½ B0957½ B03 W08F B012

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.


Zen19 vs pachi2
Moves 15 & 16.

In round 2 Zen19 played pachi2. They started with a standard joseki in the upper left corner, as shown to the right; but pachi2 played move 15 as shown, which I believe is a blunder. After Zen19 made the natural answer at 16, the two black stones are almost dead.

Zen19 vs pachi2
Moves 120 to 136.

Later in the game, the moves to the left were played. I have no comment on the fighting in the upper part of the board. But the tenukis, at 121 and 134, are hard to explain. My understanding is that the white group in the lower left is unconditionally alive, and neither of these moves changed this. (A reader has pointed out that while neither move affects the life of the white group, both affect whether it is alive with territory or alive in seki. Thus each of these moves is worth about 10 points in gote.)

Also in round 2, NiceGo19N failed to clean up against MCark, but won the game anyway even with MCark's dead stones counted as alive.

pachi2 vs AyaMC
Moves 189.

In round 3, AyaMC played move 189 as shown to the right, against pachi2. Admittedly, it was far enough behind that it had very little chance of winning. But this move is worth one point in gote, there are many bigger moves.

In round 6 stv failed to clean up against MCark, but won the game anyway even with MCark's dead stones counted as alive.

In round 7 MCark ran out of time in the clean-up phase, in a lost position against stv.

MCArk was not present on the server in round 8, and lost on time against Orego12.

Also in round 8, AyaMC obtained a won position against stv, but lost on time when it played only nine of its ten overtime stones within its first 30-second overtime period. It had been consistently using three seconds a move, and this was not quite enough. (I noticed in later games, that it used only two seconds a move when in overtime, and had no more losses on time. I don't know whether its time-handling was adjusted, or whether its connection speed improved.)

MCark was connected again in time for the start of round 9, and played its game with NiceGo19N.

In round 12 Zen19 and pachi2 played for a third time. Pachi2 had won their first two games, but Zen19 won this one, rather easily, or so it seemed.

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)
Oakfoam, running on a Cluster Compute Eight Extra Large Instance, 60.5 GB of memory 88 EC2 Compute Units (2 x Intel Xeon E5-2670, eight-core "Sandy Bridge" architecture) 3370 GB of instance storage 64-bit platform I/O Performance: Very High (10 Gigabit Ethernet) API name: cc2.8xlarge
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.
Steenvreter, running 46 threads each at 2.2 GHz, on a system whose use was generously provided by the Maastricht games and AI group.
Zen, running on a Mac Pro 8 core, Xeon 2.26GHz.