The 18th season of the Top Chess Engine Championship began on 4 May 2020 and ended on 3 July 2020. The defending champion was Leela Chess Zero, which defeated Stockfish in the previous season's superfinal. The two season 17 superfinalists qualified again for the superfinal. This time Stockfish won, winning by 7 games (+23−16=61). [1]
TCEC Grand Champion | Runner-up |
Stockfish | Leela Chess Zero |
53.5 (23) | 46.5 (16) |
← TCEC Season 17 | TCEC Season 19 → |
For this season, there are five leagues: the Qualification League (QL), League Three, League Two, League One, and Premier Division. Two engines promote in every league, with the top two engines of the Premier Division contesting a 100-game superfinal. Updates are allowed only between League Three and League Two, between League One and Premier Division, and between Premier Division and the superfinal. In a small change to previous seasons' rules, draw adjudication now occurs if the evaluations of both engines are within +/− 0.15 for five consecutive moves, after move 35. This increases the threshold of evaluation compared to +/− 0.08 for the previous season. [2]
In contrast to previous seasons, only active engines that are stronger than the best humans are invited to participate. The addition of the "active" criterion means that several veteran competitors, such as former champions Jonny and Houdini, are not participating. [3] Further, a more stringent uniqueness criterion meant that PeSTO (which shares a search algorithm with rofChade) and Komodo MCTS (which shares an evaluation algorithm with Komodo) are not participating.[ citation needed ]
The tiebreak rules for TCEC Season 18 are:
For this season, TCEC upgraded its GPU servers to four V100s, while the CPU servers largely stayed the same. [4] [5]
Ten engines participated in the Qualification League. Seven engines returned from the previous year, Monolith returned after a two-season hiatus, and two new engines (Combusken and Weiss) made their first appearances. The league turned out to be very closely contested: every engine lost at least two games, and in the final standings, only 2 points separated winner Counter from 7th-placed Combusken. This meant that seven engines were in with a chance up until the final games. Eventual 2nd-place finisher Asymptote staged a mini-comeback after a poor first round to finish second, ahead of 3rd-placed Monolith on the back of a head-to-head win. chess22k, the only engine that had promoted out of QL previously, started well but stalled in the second half and ended in 4th place. Tail-enders Bagatur and Weiss were heavily handicapped by only being able to make use of one thread while their competitors usually ran on 176, and finished with only 5/18 and 1.5/18 respectively. [6]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Counter | 18 | 9 | 6 | 3 | 12 | Advance to League 3 |
2 | Asymptote | 18 | 8 | 7 | 3 | 11.5 | |
3 | Monolith | 18 | 8 | 7 | 3 | 11.5 | |
4 | chess22k | 18 | 6 | 10 | 2 | 11 | |
5 | ChessFighter | 18 | 6 | 9 | 3 | 10.5 | |
6 | FabChess | 18 | 6 | 8 | 4 | 10 | |
7 | Combusken | 18 | 5 | 10 | 3 | 10 | |
8 | Tucano | 18 | 2 | 10 | 6 | 7 | |
9 | Bagatur | 18 | 3 | 4 | 11 | 5 | |
10 | Weiss | 18 | 0 | 3 | 15 | 1.5 |
Ten engines participated in League 3. Every engine here played in Qualification League last year, and while the top and bottom engines were unchanged, the order of the middle engines saw some shifting. Demolito took advantage of S17 QL winner Defenchess leaving for greener pastures to win League 3 with 12/18. Second place was closely contested, with Igel taking a 1-point lead after 60 games, only to see Gogobello storm from behind with a string of victories, including an impressive win as black over Demolito, and place second by 0.5 points. Meanwhile Pirarucu, which finished ahead of both Igel and Gogobello last year, placed a disappointing 6th, though it did hand Gogobello its only loss. On the other end, QL promoters Counter and Asymptote found League 3 far more unwelcoming and relegated back to QL with 7/18 and 6/18 respectively. Counter initially looked like it could hold on, starting out with 10 straight draws, but finished with 4 losses and 4 draws in its remaining games, becoming the only engine not to win a game. [6]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Demolito | 18 | 7 | 10 | 1 | 12 | Advance to League 2 |
2 | Gogobello | 18 | 5 | 12 | 1 | 11 | |
3 | Igel | 18 | 4 | 13 | 1 | 10.5 | |
4 | Minic | 18 | 4 | 11 | 3 | 9.5 | |
5 | iCE | 18 | 4 | 10 | 4 | 9 | |
6 | Marvin | 18 | 2 | 14 | 2 | 9 | |
7 | Topple | 18 | 2 | 12 | 4 | 8 | |
8 | Pirarucu | 18 | 2 | 12 | 4 | 8 | |
9 | Counter | 18 | 0 | 14 | 4 | 7 | Relegate to QL |
10 | Asymptote | 18 | 1 | 10 | 7 | 6 |
Booot, Chiron, and ChessBrainVB, which did not play in the previous season because they did not run on Wine, all returned to play this season in League Two. Among the competitors three engines quickly distanced themselves from their rivals: Booot, Pedone and Winter. Booot was comfortably in the lead for most of the division and was the first to promote, while Winter trailed after losing a game against Pedone. In one of the final games of the league, Winter scored a win against Booot, which put it half a point ahead of Pedone; however, it was all for naught as Pedone drew its game in hand against Chiron, which tied the scores between the two and let Pedone qualify on tiebreak.
At the bottom of the table, in a repeat of League Three, the two promoted engines Demolito and Gogobello found the competition much stiffer and were both relegated back to League Three. [6]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Booot | 18 | 8 | 9 | 1 | 12.5 | Advance to League 1 |
2 | Pedone | 18 | 6 | 12 | 0 | 12 | |
3 | Winter | 18 | 7 | 10 | 1 | 12 | |
4 | Vajolet | 18 | 3 | 12 | 3 | 9 | |
5 | Chiron | 18 | 3 | 11 | 4 | 8.5 | |
6 | Wasp | 18 | 3 | 11 | 4 | 8.5 | |
7 | ChessBrainVB | 18 | 1 | 13 | 4 | 7.5 | |
8 | Nemorino | 18 | 2 | 11 | 5 | 7.5 | |
9 | Demolito | 18 | 2 | 10 | 6 | 7 | Relegate to League 3 |
10 | Gogobello | 18 | 1 | 9 | 8 | 5.5 |
Fire, which had performed respectably in last season's Premier Division in spite of not having been updated for over a year, won League One. Along with last season's promotion rival rofChade, it did not lose a game the entire league, with both finishing comfortably above third-placed Booot. In contrast, the middle of the table was fiercely contested. Booot was the only engine to score two wins against its mid-table rivals, defeating Fritz and ScorpioNN, but it lost a game to last-place Pedone. Defenchess lost a game to Xiphos, but it along with Fritz was able to 2–0 Pedone, thereby taking 4th and 5th respectively. Last season's Premier Division engine ScorpioNN, as well as League One contender Xiphos, both performed solidly and lost only one game; however, they also only scored one win which was insufficient to fight for the top spots. At the other end of the table, promoted engine Pedone was quickly outclassed, losing eight games. For the other relegation spot, both Arasan and RubiChess failed to score any wins, but Arasan lost only one game, leaving RubiChess to relegate. [6]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Fire | 18 | 5 | 13 | 0 | 11.5 | Advance to Premier Division |
2 | rofChade | 18 | 4 | 14 | 0 | 11 | |
3 | Booot | 18 | 3 | 13 | 2 | 9.5 | |
4 | Defenchess | 18 | 3 | 13 | 2 | 9.5 | |
5 | Fritz | 18 | 2 | 14 | 2 | 9 | |
6 | ScorpioNN | 18 | 1 | 16 | 1 | 9 | |
7 | Xiphos | 18 | 1 | 16 | 1 | 9 | |
8 | Arasan | 18 | 0 | 17 | 1 | 8.5 | |
9 | RubiChess | 18 | 0 | 15 | 3 | 7.5 | Relegate to League 2 |
10 | Pedone | 18 | 1 | 9 | 8 | 5.5 |
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In the Premier Division, Stoofvlees (which had not been updated since Season 17) took a surprising lead after the first round robin. It recorded the only double-kill (winning with both sides of the same opening) against rofChade, and by the end of the first round robin, was on +4 while pre-tournament favorites[ citation needed ] Stockfish, Leela and AllieStein were only +2. The lead did not last, however. Stockfish played a sterling second round robin, including a win against both Stoofvlees and AllieStein, to take first place. Leela also closed the gap by not losing any games while defeating Ethereal, rofChade and Fire. By the third round robin, Stockfish was effectively qualified for the superfinal, while the second slot was still up for grabs. Leela effectively eliminated Stoofvlees after the latter blundered a simple tactic (see diagram). AllieStein was only a win behind, however, and had superior tiebreakers to boot. Leela defeated Ethereal, only for AllieStein to keep pace by beating Komodo. It looked as though Stoofvlees' blunder might've been decisive to Leela qualifying for the superfinal. The question was finally settled in game 164 when AllieStein lost the reverse game to Komodo, which qualified Leela for the superfinal. Both Leela and first-placed finisher Stockfish did not lose a game in the division. [6]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Stockfish | 42 | 9 | 33 | 0 | 25.5 | Advance to Superfinal |
2 | Leela Chess Zero | 42 | 7 | 35 | 0 | 24.5 | |
3 | AllieStein | 42 | 7 | 33 | 2 | 23.5 | |
4 | Stoofvlees | 42 | 7 | 32 | 3 | 23 | |
5 | Komodo | 42 | 4 | 34 | 4 | 21 | |
6 | Ethereal | 42 | 0 | 38 | 4 | 19 | |
7 | rofChade | 42 | 1 | 30 | 11 | 16 | Relegate to League 1 |
8 | Fire | 42 | 0 | 31 | 11 | 15.5 |
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The superfinal was contested between reigning champion Leela Chess Zero and last season's runner-up Stockfish. [7] The 100-game match began with both engines winning in a King's Indian Defense, before Stockfish took the lead by winning three consecutive openings, including a stunning performance with the white pieces in Game 8, tactically outclassing Leela in the middle-game. After a balanced interlude, Stockfish won game 24 to open up a commanding 4-point lead, the largest deficit Leela had ever faced in a superfinal. Leela finally got back to winning ways with a strong performance in game 29, and narrowed the gap further by winning game 33. However, with wins in games 52, 56 and 58, Stockfish established its dominance once again. Leela fought back with a win in game 63, and then followed this up by winning game 65 (see game analysis below) with what was perhaps the single best performance from either engine in the entire superfinal; Leela played an astonishing queen sacrifice on move 21 that Stockfish not only didn't spot, but then took a further three moves to work out it was completely winning – GM Matthew Sadler would later call this game Leela's queen sac Immortal. [8] However, Stockfish countered with wins in games 68, 77, 88 and 92 to secure what would prove to be a decisive lead. With eight games left, Leela needed to win seven of them in order to win. It managed to win game 93, but subsequently lost the reverse in game 94, which gave Stockfish an unassailable lead. Leela scored a consolation win in game 97 to make the final score +23−16=61 in favour of Stockfish. [6]
One game pair in the superfinal stood out as unique: games 17-18 featured an opening which, to GM Sadler's knowledge, was playable. However, both finalists evaluated the book exit position (diagram) as providing a decisive advantage for White. GM Sadler opined that these two games might eventually be the final refutation of the entire variation. [9]
Pos | Engine | Pld | W | D | L | Pts | Qualification |
---|---|---|---|---|---|---|---|
1 | Stockfish | 100 | 23 | 61 | 16 | 53.5 | TCEC Season 18 Champion |
2 | Leela Chess Zero | 100 | 16 | 61 | 23 | 46.5 |
In an article published shortly after the superfinal, GM Matthew Sadler wrote that Stockfish was a deserving winner: its developers had been producing patches at a frantic pace, it showed an exceptional tactical eye, and it even looked like it had learned how to play the King's Indian Defense. The superfinal produced numerous interesting games, but GM Sadler highlights two in particular for their creativity and beauty. [9] Most of the notes below are by GM Sadler.
This opening featured a dubious line of the Triangle setup against the Queen's Gambit. After successfully defending the Black position in Game 7, Stockfish unleashed this demolition job with the white pieces.
White: Stockfish (chess) Black: Leela Chess Zero Opening: Queen's Gambit Declined ( ECO D31)
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8 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | 8 | |||||||
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1. d4 d5 2. c4 c6 3. Nf3 e6 4. Nc3 dxc4 5. Bg5 f6?! 6. Bd2 b5 (see diagram)
7. a4
7... b4 8. Ne4 f5
9. Ng3 Nf6 10. e3
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8 | ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() | 8 | |||||||
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10... Ba6 11. Be2 (see diagram)
11... c5
12. dxc5 Nbd7
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13. c6 Nc5 14. Nd4 f4 (see diagram)
15. Nh5 Nfe4
16. 0-0
16... e5
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17. Bxb4 exd4 18. Nxf4 Rb8 (see diagram)
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19. exd4 Rxb4 20. Re1
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20... Be7 21. Bh5+ g6 22. dxc5 Qxd1 23. Raxd1 Nf6 (see diagram)
24. Bxg6+ hxg6 25. Nxg6 Rh7 26. Rd6 (see diagram)
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26... Ne4 27. Rxe4 Rxb2
28. h3 c3 29. Rf6 (see diagram)
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29... Kd8 30. Nxe7 Rxe7 31. Rf8+ Kc7 32. Rxe7+ Kxc6 33. Rf6+ Kd5 34. Re3 Rb1+ 35. Kh2 c2 36. Rc3 Bd3 37. Rd6+ Ke4 38. Rdxd3 c1=Q 39. Rxc1 Rxc1 40. Rd7 a5 41. Rf7 Rxc5 42. g4 Kd5 1–0
This game was what GM Sadler called the other gem of the superfinal. It featured a sharp and topical line of the Bogo-Indian in which Leela played a positional queen sacrifice that led to a long-term bind and an eventual victory. Most of the notes to this game are also by GM Sadler. [9]
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1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Nbd2 0-0 5. a3 Be7 6. e4 d5 7. e5 Nfd7 8. Bd3 c5 9. h4 (see diagram)
9... g6 10. 0-0
10... Nc6
11. Nb3 Bxh4
12. Bh6 Re8 13. Re1
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13... cxd4 14. Qc2 (see diagram)
14... dxc4
15. Bxc4 Nb6 16. Rad1
16... Bd7 17. Nc5
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17... Rc8 18. b4 Nxc4 19. Qxc4 (see diagram) Be7 20. Ne4 Nxb4
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21. Qxb4
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21... Bxb4 22. axb4 (see diagram) f5
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23. Nf6+ Kh8
24. Rxd4 Rc7 25. Red1 Re7 26. b5
26... b6 27. Kh2 Rb7 28. Ng5 Qc8 29. R1d2 Rc7
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30. Rd6 Rb7 31. R2d4 Rc7 32. Rd1 Rb7 33. R6d4 Rc7 34. f4 (see diagram) Rb7 35. Nxe6 Rxe6 36. Nxd7 Kg8 37. Nf6+ Kf7
38. Rd8 Qc5
39. Nxh7
39... Re8 40. e6+ Rxe6 41. Ng5+ Kf6 42. Rf8+ Qxf8 43. Bxf8 (see diagram) Rc7 44. Rd4 Rb7 45. Kg3 Rc7 46. Rd3 Rb7 47. Kh4 Rc7 48. Kg3 Rc4 49. Rd7 Re3+ 50. Kf2 Rxf4+ 51. Kxe3 Ra4 52. Be7+ Ke5 53. Kf3 1–0
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In chess, an X-ray or X-ray attack is a tactic where a piece indirectly controls a square from the other side of an intervening piece. Generally, a piece performing an X-ray either:
The Philidor Defence is a chess opening characterised by the moves:
Owen's Defence is an uncommon chess opening defined by the moves:
Rosendo Carreon Balinas Jr. was a chess grandmaster from the Philippines. FIDE awarded him the International Master title in 1975 and the International Grandmaster title in 1976. He was Philippines' second chess grandmaster. Balinas was a lawyer by profession, as well as an award winning chess writer and journalist. He also unsuccessfully ran for representative of Rizal's 1st district in the 1994 special election.
Nolot is a chess test suite with 11 very difficult positions from real games. They were compiled by Pierre Nolot for the French chess magazine Gambisco and posted on the rec.games.chess Usenet group in 1994. Some of these positions were particularly hard to solve for chess engines at the time.
The World Chess Championship 2006 was a match between Classical World Chess Champion Vladimir Kramnik and FIDE World Chess Champion Veselin Topalov. The title of World Chess Champion had been split for 13 years. This match, played between September 23 and October 13, 2006, in Elista, Kalmykia, Russia, was to reunite the two World Chess Champion titles and produce an undisputed World Champion.
The World Chess Championship 2010 match pitted the defending world champion, Viswanathan Anand, against challenger Veselin Topalov, for the title of World Chess Champion. The match took place in Sofia, Bulgaria from 24 April to 13 May 2010, with a prize fund of 2 million euros. Anand won the final game to win the match 6½–5½ and retain the title.
A World Chess Championship was played between challenger Max Euwe and title-holder Alexander Alekhine in various cities and towns in the Netherlands from 3 October to 16 December 1935. Euwe was the winner by overcoming a three-point deficit as late as the ninth game.
The 1981 World Chess Championship was played between Anatoly Karpov and Viktor Korchnoi in Merano, Italy from October 1 to November 19, 1981. Karpov won with six wins against two, with 10 draws. The two players had already played against each other in the World Chess Championship match 1978 in the Philippines, when Karpov also won.
Houdini is a UCI chess engine developed by Belgian programmer Robert Houdart. It is influenced by open-source engines IPPOLIT/RobboLito, Stockfish, and Crafty. Versions up to 1.5a are available for non-commercial use, while 2.0 and later are commercial only.
Top Chess Engine Championship, formerly known as Thoresen Chess Engines Competition, 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. The tournament has attracted nearly all the top engines compared to the World Computer Chess Championship.
The World Chess Championship 2018 was a match between the reigning world champion since 2013, Magnus Carlsen, and the challenger Fabiano Caruana to determine the World Chess Champion. The 12-game match, organised by FIDE and its commercial partner Agon, was played at The College in Holborn, London, between 9 and 28 November 2018. The games were broadcast on worldchess.com and by NRK.
Leela Chess Zero is a free, open-source, and deep neural network–based chess engine and volunteer computing project. Development has been spearheaded by programmer Gary Linscott, who is also a developer for the Stockfish chess engine. Leela Chess Zero was adapted from the Leela Zero Go engine, which in turn was based on Google's AlphaGo Zero project. One of the purposes of Leela Chess Zero was to verify the methods in the AlphaZero paper as applied to the game of chess.
The World Chess Championship 2021 was a chess match between the reigning world champion Magnus Carlsen and the challenger Ian Nepomniachtchi to determine the World Chess Champion. It was held under the auspices of FIDE and played during Expo 2020 at Dubai Exhibition Centre in Dubai, United Arab Emirates, between 24 November and 12 December 2021. It was originally scheduled for the latter half of 2020 but was postponed until 2021 because of the COVID-19 pandemic. As a result, this is the first sporting event to be held at an international exposition since the 1904 Summer Olympics during the Louisiana Purchase Exposition in St. Louis, United States.
The 14th season of the Top Chess Engine Championship took place between 17 November 2018 and 24 February 2019. Stockfish was the defending champion, having defeated Komodo in the previous season's superfinal.
The 15th season of the Top Chess Engine Championship began on the 6 March 2019 and ended on 12 May 2019.
The 16th season of the Top Chess Engine Championship began on 15 July 2019 and ended on 13 Oct 2019.
The 17th season of the Top Chess Engine Championship began on 2 January 2020 and ended on 22 April 2020. TCEC Season 16 3rd-place finisher Leela Chess Zero won the championship, defeating the defending champion Stockfish 52.5-47.5 in the superfinal.
The 19th season of the Top Chess Engine Championship began on 6 August 2020 and ended on 16 October 2020. The season 19 superfinal was a rematch between Stockfish and Leela Chess Zero, the same two engines that had contested the superfinal in the previous two seasons. Stockfish, the defending champion, won by 9 games.
The 20th season of the Top Chess Engine Championship began on 1 December 2020 and ended on 1 February 2021. The defending champion was Stockfish, which defeated Leela Chess Zero in the previous season's superfinal. The season 20 superfinal was a rematch between the same two engines. Stockfish once again came out ahead, winning by 6 games.