Zen (go program)

    Keywords: Software

Zen is a strong Go engine by an individual Japanese programmer Yoji Ojima (cluster parallelism is added by Hideki Kato). On KGS several bots run engine maintaining ranks between 5d and 7d (in Spring 2016): Zen19, Zen19b, Zen19D, Zen19S, Zen19X and Zen19n. Zen was the first bot to hold a KGS 3d rating for more than 20 rated games in a row, and a blitz version seems to be holding 5 dan ratings in 2011. It was also the first to hold a 2d and 1d rating for more than 20 games, respectively. Hardware used to run Zen19 on KGS: Mac Pro 8 core, Xeon 2.26GHz.

It won Computer Olympiads in 2009 (Pamplona, Spain; running on the slowest hardware among the competitors) 2011 (Tilburg), 2013 (Yokohama), and 2015 (Leiden). In 2012, Zen beat Takemiya Masaki once with a handicap of 5 stones (11 points) and once with 4 stones (20 points). In 2016, Zen beat Cho Hyeyeon with a handicap of 2 stones.

Zen was first released commercially under the name Tencho no Igo Zenith Go on 18 September 2009.

  • Version 2 released on August 27, 2010.
  • Version 3 released on 30 September 2011.
  • Version 4 released on 27 July 2012.
  • Version 5 released on 13 December 2013.
  • Version 6 released on 3 June 2016.

[ext] Website for the Japanese version 6

[ext] Website for the English version 6 (this has an English interface for menu options and game results. Only a few commentary areas and tsumego comments remain in japanese.)

See latest go software updates for current version information.

(See Zen for disambiguation])

In 2011, several different experiments of Zen started playing on KGS:

Name Rating Time Hardware KGS Archive
Zen19N 4D 20 Minutes + 30 seconds Byo-Yomi Mac Pro 8 cores, Xeon 2.26 GHz [ext] Zen19N
Zen19B 5D 15 seconds per move Mac Pro 8 cores, Xeon 2.26 GHz [ext] Zen19B
Zen19D 6D 15 seconds per move Mini-cluster of 6 PCs [ext] Zen19D
Zen19S 5D 20 Minutes + 30 seconds Byo-Yomi Mini-cluster of 6 PCs [ext] Zen19S
Zen19 6D 15 seconds per move [ext] Zen19
Zen19X 7D 15 seconds per move [ext] Zen19X

Four versions active in 2016: Zen19, Zen19S, Zen19A and Zen19X. Zen19 is the first program to enter GoKGS top 100 players, ranked 92 as of January 17, 2016. Zen19X is the first 7D bot in blitz game, ranking in top 50 GoKGS player. Zen 19A is the first bot to reach 8D, ranking in the top 20.


Zen (go program) last edited by on July 28, 2016 - 16:30
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