OpenChess

General Information

Each game presented on this site is played with a time control of 40 moves in 100 minutes, the next 20 moves in 50 minutes, then finally 20 minutes for the rest plus 10 seconds added per move at this last time control. If an engine loses on time for various reasons the result will stand - hence the game will not be replayed. The openings are always limited to 12 moves / 24 plies when using either a pgn file or a neutral opening book.

Engine Configuration
Each engine is allowed to use up to ~4 GB of hash and is allowed to use up to all six cores of the processor, if this is supported. Pondering or "permanent brain" is not allowed in TCEC so it is always disabled. If an engine executable supports the pop_cnt instructions it will be preferred over the non-pop_cnt executable, the same applies to 64-bit builds being preferred over 32-bit builds. It is not allowed to change the engine configuration or parameters, so the default settings for each engine are always used. In general, most commercial and free engines are available in TCEC.

The TCEC Division System
There are currently 3 seperate TCEC Divisions: 1, 2 and 3 where 1 is the "Premier" Division. Each Division consists of 8 engines. In each season, 56 games will be played per Division, which means a double round robin where everyone of the 8 participating engines play each other twice. The openings are made so that they are random per engine pair in rounds 1-7. In rounds 8-14 the colors are reversed, with the same openings and pairs, so all in all this means that each engine plays both black and white of the same position versus the same opponent.

If an engine currently scheduled to play in any Division has been released in a new version, this new version takes the place of the old version, but only if the Division hasn't started yet. So during a Division being played, no engine upgrades are allowed. When a season ends, meaning that all 3 Divisions and the Elite Match have been played, the top three engines are promoted to the Division above, and the bottom three engines are demoted to play in the Division below for the next season. In Division 3, the three bottom engines will be replaced by three new engines (or previous engines which has been released in a newer version) so they are out of the TCEC system for the coming season. If necessary, tiebreaks can be used to determine promotions and demotions. The first tiebreak critera is the Sonneborn-Berger. If still a tie, the greatest number of wins decides. In case of still being tied, the direct encounter between the tied engines is the last tiebreak.

TCEC Elite Matches
After all the Divisions has finished their group play, engine number 1 and 2 from Division 1 will meet in an "Elite Match" of 40 games. If there are several engines placed as number 1 or 2 in Division 1, then the same tiebreaks described above are used. The match is played with 20 different openings so that each engine plays both black and white of the same position. In the case of a drawn match, 8 rapid games with a time control of 25+10 are played. If still tied, then 8 blitz games with a time control of 4+2 are played. The winner of this match becomes the "TCEC Season X Champion" and this ends the current season.

If an engine loses on time for various reasons the result will stand - hence the game will not be replayed

BB+ wrote:

If an engine loses on time for various reasons the result will stand - hence the game will not be replayed

Two questions: how many time losses have you had so far? And if an engine has a "Time Buffer" or the like [particularly to soften the last move of a "movestogo" time control], do you use it?

I would also say that the GUI adjucation for draws (see the Rules page) is a bit dodgy in my opinion, but I really don't have enough data to suggest anything different. [For instance, can anyone with a large database of longish TC computer games determine how many games which would be drawn under the TCEC specs do in fact end up being decisive?]

PS. I agree that the quality of the games is the only reason why I find these competitions to be interesting.