Top Chess Engine Championship, formerly known as Thoresen Chess Engines Competition (TCECor nTCEC), is a computer chess tournament that has been run since 2010. It was organized, directed, and hosted by Martin Thoresen until the end of Season 6; from Season 7 onward it has been organized by Chessdom. It is often regarded as the Unofficial World Computer Chess Championship because of its strong participant line-up and long time-control matches on high-end hardware, giving rise to very high-class chess.
After a short break in 2012, TCEC was restarted in early 2013 (as nTCEC) and is currently active (renamed as TCEC in early 2014) with 24/7 live broadcasts of chess matches on its website.
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 several qualifying stages and one "superfinal", where the top two chess engines play 100 games to win the title of "TCEC Grand Champion". In the superfinal, each engine plays 50 openings, once as each side. Beginning in Season 11 in 2018, a division system was introduced; the top 2 engines in each division are promoted, and the bottom 2 are relegated. Currently there are 5 divisions (a Premier division, and divisions 1-4); newcomers generally start in division 4.
Pondering is set to off. All engines run on mostly the same hardware and use the same opening book, which is set by the organizers and changed in every stage. Large pages are disabled but access to various endgame tablebases is permitted. Engines are allowed updates between stages; if there is a critical play-limiting bug, they are also allowed to be updated once during the stage. If an engine crashes 3 times in one event, it is disqualified to avoid distorting the results for the other engines. 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 criterion for entering into the competition, other than inviting the top participants from various rating lists. Initially, the list of participants was personally chosen by Thoresen before the start of a season. His stated goal was to include "every major engine that is not a direct clone". However, Shredder's developers have declined to enter it in the competition. Usually chess engines that support multiprocessor mode are preferred (8-cores or higher). Both Winboard and UCI engines are supported.
3 matches followed by 2 tournaments then alternating between match and tournament until there were 6 tournaments and 5 matches
3 division (1 through 3) followed by elite match
Same as Season 1 but with 6 divisions (A through F)
2 stages (1 followed by 2a). Season not completed.
Same as Season 2 but with 4 more tournaments (Stages 2b, 3 and 4 followed by a superfinal, in that order)
4 stages (1 through 4) followed by a superfinal
Same as Season 5 but stage 1 was stage 1a through c and a Chess960 tournament after the superfinal
Same as Season 6 but no stage 1c nor tournament after the superfinal
Same as Season 7 but no stage 4
Same as Season 8 but between the stage tournaments and superfinal was a rapid tournament
2 stages (1 followed by 2) then superfinal then 2 other tournaments (rapid followed by blitz)
11 - 14
5 divisions (labelled 4, 3, 2, 1, and Premier) of 8 engines each. Top 2 of each division promote, bottom 2 relegate; top 2 of Premier play the superfinal. Seasons 13 and 14 also had a cup, which were a 5-round single elimination tournament.
Shredder (White) is on the brink of being checkmated, but found the defensive resource 46. Bb3 Nxb3 47. Qf4+ gxf4 48. Rb7+ Kc8 49. Rc7+ Kd8, etc. If Black captures the white rook, it is stalemate.
Date and game title info
Notes (material calculations excluding king)
27 September 2010 (Match 3, Game 3 of Round 23, Game of the Month 1)
Taking the knight results in eventual mate or taking the queen results in a pawn, knight, bishop each for black vs a knight and rook each plus 3 pawns
As black, the link suggests Qa7 but leads to a position about 25 moves later where white basically can do a king vs queen mate (however there is another passed pawn, which can be eventually used as a 2nd queen in a 2 queen electrical fence checkmate)
^Until season 13, all engines ran on the same hardware; however in season 13 the entrance of two neural network engines caused TCEC to use different hardware for the two types of engines. "TCEC Season 13 – the advance of the NNs". Chessdom. 2 August 2018.