Top Chess Engine Championship

Overview

The TCEC competition is divided into Seasons, where each Season happens over a course of a few months, with matches played round-the-clock and broadcast live over the internet. Each season is divided into 4 qualifying stages and 1 Superfinal, where the top two chess engines battle it out over a series of 64 games to win the title of TCEC Grand Champion.

The time control in all events is 120+30 (120 minutes + 30 seconds added per move for the whole game) and pondering is set to off. The Opening Book is taken from recent strong human Grandmaster tournaments, is truncated to the first 6 or 8 moves, and is changed in every Stage. Engines are allowed updates between stages, unless there is a critical play-limiting bug, in which case the engine are allowed to be updated once during the stage. TCEC generates its own elo rating list from the matches played during the tournament. An initial rating is given to any new participant based on its rating in other chess engine rating lists.

There is no definite criterium for entering into the competition, other than inviting the top participants from various rating lists. The list of participants is personally chosen by Thoresen before the start of any new season. His stated goal is to include "every major engine that is not a direct clone". Usually chess engines that support multiprocessor mode are preferred (8-cores or higher). Both Winboard and UCI engines are supported. Large pages are disabled but access to various endgame tablebases is permitted.

¹ Rules may differ from season to season

GUI adjudication rule

A game can be drawn by threefold repetition or fifty-move rule. However, a game can also be drawn at move 40 or later if the eval from both playing engines are within +0.05 to -0.05 pawns for the last five moves, or ten plies. If there is a pawn advance or a capture, this special draw rule resets and starts over. On the website, this rule shows as "Distance in plies to TCEC draw rule". It adjudicates as won for one side if both playing engines have an evaluation of at least 6.50 pawns (or -6.50 in case of a black win) for four consecutive moves, or eight plies - this rule is in effect as soon as the game starts. The GUI also adjudicates tablebase endgame positions (with 5-men or less) automatically.

Technical specifications (Season 7)

The TCEC Computer: CPUs: 2 x 8 core Intel Xeon E5-2689 @ 3300 MHz CPU Coolers: 2 x Corsair H80i Motherboard: Asus Z9PE-D8 WS RAM: 64 GB Kingston KVR16R11D4K4/32 Reg/ECC PSU: Corsair AX 760 SSDs: 2 x Samsung 840 Pro 128 GB @ Raid 0 Case: Silverstone Raven RV03B-WA OS: Windows 7 Professional Configuration: Graphical User Interface (GUI): cutechess-cli (custom) Protocol: Winboard, UCI Large Pages: OFF Number of Cores/Threads (per engine): 8 or 16 Split Depth: DEFAULT Main Hash Size: 16 GB (Maximum) Minor Hash Size: 1 GB Engine Opening Book: OFF Endgame Tablebases: 6-men Syzygy, 5-men Nalimov, 5-men Gaviota (cp2), 5-men Shredderbases and 5-men Robbobases (Totalbases + Triplebases) supported Tablebase Cache: 1024 MB (Maximum) Ponder/Permanent Brain: OFF Contempt/Draw Score: DEFAULT

N.B.: tablebases were disabled for all engines for the whole of Season 7.

Technical specifications (Season 8)

The TCEC Computer: CPUs: 2 x 10 core Intel Xeon E5-2650v3 @ 2600 MHz Motherboard: Supermicro X10DRL-i RAM: 128 GB Samsung DDR4 Reg/ECC SSD: Kingston 64 GB Chassis: Supermicro OS: Windows Server 2012 R2 Configuration: Protocol: Winboard, UCI Large Pages: OFF Number of Cores/Threads (per engine): max. 20 Split Depth: DEFAULT Main Hash Size: 32 GB (Maximum) Minor Hash Size: 4 GB Engine Opening Book: OFF Endgame Tablebases: 5-men Syzygy, 5-men Nalimov, 5-men Gaviota (cp2) supported Tablebase Cache: 32 MB (irrelevant since whole TB resides in RAM) Ponder/Permanent Brain: OFF Contempt/Draw Score: DEFAULT

Technical specifications (Season 9)

The TCEC Computer: Season 9 Stage 1-3 + Rapid server CPUs: 20 Cores -> 2 x Intel Xeon E5 2630 v4 @ 2.4 GHz Motherboard: Supermicro X10DRL-i RAM: 64 GB DDR4 ECC SSD: 256 GB Chassis: Supermicro OS: Windows Server 2012 R2 Season 9 Superfinal server CPUs: 44 Cores -> 2 x Intel Xeon E5 2699 v4 @ 2.8 GHz Motherboard: Supermicro X10DRL-i RAM: 128 GB DDR4 ECC SSD: Crucial CT250M500 240 GB Chassis: Supermicro OS: Windows Server 2012 R2

Tournament results

¹ Originally named "nTCEC Season 1" ² Originally named "nTCEC Season 2" ³ Special Chess960 quad-round-robin tournament consisting of the top 8 engines from Season 6 that had support for Chess960 ⁴ Season 7 did not use endgame table bases. Stage two did not use opening books.

Notable games

Pre-TCEC:

Stockfish vs Houdini, Match 3, 23.1, "Game of the Month 1", 2010-07-27, 1–0

Shredder vs Naum, Tournament 1, 1.3, "Game of the Month 2", 2010-08-01, 0–1

Houdini vs Rybka, Tournament 5, 8.3, "Game of the Month 3" 2010-11-26, 1–0

Season 1-3:

Rybka vs Houdini, TCEC S1, Elite Match, 1.1 0–1 Houdini sacrifices three pawns for piece activity and defeats the reigning computer chess champion Rybka in this game, popularly dubbed as the "Houdini Immortal".

Houdini vs Rybka, TCEC S2, Elite Match, 19.2, 1–0 Houdini exploits minor inaccuracies by Rybka with a sacrifice.

Season 4:

Shredder vs Gull, TCEC S4, Stage 2b, 14.3, ½–½ Shredder pulls off a save, at the brink of defeat.

Season 5:

Gull vs Komodo, TCEC S5, Stage 3, 2.2, 0–1<

Houdini vs Stockfish, TCEC S5, Stage 3, 17.4, 0–1 Stockfish, thanks to its heavy depth-oriented search, out-calculates Houdini, and wins the game.

Season 6:

Komodo vs Stockfish, TCEC S6, Stage 3, 1, 1-0

Season 9:

Stockfish, vs Houdini TCEC Superfinal Game 15 2016 0- 1 Houdini 5 sacrifices its Queen but still loses to Stockfish