In a fitting end to the season, Stockfish once again defeated its rivals to win the final event – the Fischer Random Chess final, thus completing a quadruple crown at the Top Chess Engine Championship! The four titles of Stockfish: Stockfish wins TCEC League / Stockfish wins TCEC Cup / Stockfish wins TCEC Swiss / Stockfish wins TCEC Fischer random More: TCEC official website
One might be tempted to say “of course Stockfish was going to win” after the results of the Leagues and Swiss, the FRC competition actually had quite a bit of drama. The group stages kept the top engines away from one another in the first stage, with most viewers expecting the Premier Division engines to qualify smoothly. It didn’t happen. In League A, Stoofvlees was the first casualty as a loss to Stockfish coupled with a strong performance by Rubichess led to Rubichess qualifying, tied for first with Stockfish. Group B, the only league without the “Big Three” (Komodo, Leela and Stockfish), still had three strong Premier Division-level engines in Berserk, rofChade and SlowChess. The three drew every game against each other, with rofChade narrowly winning the group and SlowChess eliminated on tiebreak.
League C served up a major surprise as Ethereal, playing with a special net optimized for FRC, won the group ahead of Leela and ScorpioNN. The three engines again drew every game against each other, but Ethereal kept pace with Leela as they smashed the lower-ranked engines, eventually taking first place on tiebreak. League D yielded an even bigger surprise as Revenge finished clear first, half a point ahead of Komodo Dragon.
With only Stockfish of the Big Three winning its League, the semifinals resulted in a Group of Death – all three of the Big Three were placed in Semileague 1. The high bias book led to a lot of decisive games, but Leela scored a rare double kill over rofChade to win the semileague, inflicting Stockfish’s first lost opening of the season on the way. Meanwhile Stockfish continued to dominate Komodo Dragon, winning an opening against it. As a result, Komodo Dragon was eliminated and failed to make the final league. Semileague 2 was less eventful, as Ethereal continued to play well, defeating all its rivals at least once and scoring another rare double kill over RubiChess. Berserk finished second, comfortably above Revenge.
It was only in the Final League that the streak of surprises ended. Stockfish and Leela left Ethereal and Berserk in the dust, scoring heavily against both engines. The two engines finished equal first, with Stockfish winning the league only on r-mobility tiebreak. Ethereal and Berserk also finished equal 3rd-4th, but Ethereal had the better head-to-head score, capping a very successful campaign.
The finals started with Stockfish winning the third and sixth openings. When Stockfish further won the 13th opening, it looked like the final might turn into a rout. Leela won the 15th and 17th openings, narrowing the gap, but Stockfish had the last say with victories in the 21st, 22nd and 25th openings. The final score is +17 -13 =20 in favor of Stockfish. Although Leela played second fiddle again, it is still won three openings against Stockfish. In a season where no other engine managed that feat, this itself is an achievement. I for one am curious what the Leela developers come up with next. They have already implemented dag-bord (short for “Directed Acyclic Graph” and “Backup-Only Repetition Draws”) for the FRC leagues with apparent success. If they can find more elo-gaining innovations, Stockfish might encounter more resistance next season.
Season 22 will close with some bonus rounds, beginning with the DFRC – double Fischer Random Chess where the starting position is not the same for both players. Find all games live at https://tcec-chess.com.
Article by Low
