Leela Chess Zero wins the TCEC Subfinal

True to her Petrosian-esque reputation of a strong match player who does not often win tournaments, Leela Chess Zero defeated Komodo Dragon 54.5-45.5 (+24 -15 =61) to win the TCEC Subfinal. The match started out closely contested, with Leela scoring wins in games 1 & 5 before Komodo Dragon evened the score with its own wins in games 7 & 13. Three draws later, Leela regained the lead with a win in game 17, followed by two more wins in games 21 and 23 before Komodo Dragon fought back to win game 25.There followed a bloody series of games where both engines took turns to win games – but not openings – before Komodo Dragon once again evened the score by winning games 34 and 38. This was as far as Komodo Dragon got however, as Leela won game 39 and never lost the lead again. Living up to bookmaker Jeroen Noomen’s observation that decisive games dry up as the match progresses, the second half of the Subfinal was less bloody, but there were more decisive openings. If engines really do get tired, Komodo Dragon actually played this match with a substantial handicap since it had just played a 100-game superfinal! Upcoming: TCEC Cup jubilee edition starts today!

Lc0’s victory reignited an old debate about whether the Premier Division was fair, as it had “failed” to select the two strongest engines for the Superfinal. Still, even Leela superfan mrbdzz agreed that the Komodo and Leela were quite close in strength, resulting in an exciting match. Furthermore, Stockfish was kibitzing the Subfinal and it pointed out several winning moves that both Leela and Komodo missed. Grandmaster Matthew Sadler agreed, pointing out that there was more of a difference between Komodo Dragon’s and Leela’s styles than Stockfish/Komodo. The Subfinal was also something of a success for GM Sadler, since he evened the “bookmaker’s score” with Jeroen – in this informal competition between the two bookmakers, Jeroen had “won” the Superfinal (there were more decisive openings selected by Jeroen in the Superfinal), but the reverse happened in the Subfinal. Read more: Matthew Sadler explains How to Maintain Your Chess Strength

With the conclusion of the Subfinal, next on the agenda is the 32-player TCEC Cup. In the last edition of the Cup, Stockfish had finished first, Leela second, and Komodo third. Although Stockfish is undoubtedly still the hot favorite to win the Cup, we’ll see several up-and-coming engines play against their higher-ranked peers. Koivisto and Berserk, who had just missed out on promotion from League 3 and League 1 respectively, will be especially keen to make an early statement on their Premier Division credentials next season. All games are available live at https://tcec-chess.com/.

Article by Low