Article by Low
League 2 of TCEC Season 23 has ended. Minic emerges victorious, comfortably ahead of the competition, while Arasan, World Computer Chess Champion Fritz, and Nemorino promoting alongside the division winner. See the final L2 standings here
With a new season comes a new lineup, as inactive engines are removed and new ones play for the first time. This season, a reorganized Qualification League (QL) used the Swiss format, with all games played from the opening position. Velvet – which had significantly overperformed in the Swiss last season – won the division with 13/18, pulling off a 2-0 win against pre-tournament favorite BlackMarlin in the process. From there, however, a mere 1.5 points separated 3rd-place Weiss from 14th-place Amoeba. Weiss, Winter and ChessFigher finished on 10.5/18, with a full five engines half a point behind. The luck of the tiebreaks saw ChessFighter as the only engine not promoting, although to be fair, ChessFighter had lagged the leaders for most of the division, and had not played any of the four engines that placed above it. At the other end of the table, fan favorite Tomitank was crushed by all its rivals, and it scored only 0.5 points, from a draw against Asymptote. This did not stop its many fans from cheering for it however – with an elo rating of “only” 2992, it is the closest we have to a human playing in TCEC. Go Tomi!
Unlike QL, League 2 used the traditional double round robin format of the TCEC. One of the participants was newly-crowned World Computer Chess Champion Fritz. One might ask, how is Fritz the World Computer Chess Champion when Stockfish was far and away the strongest engine last season? By common consensus among engine developers, the main reason is the different formats of the WCCC and TCEC – the WCCC allows the developers to use an opening book. Although opening books don’t magically bridge 250-elo differences, a good book makes an engine very difficult to beat, especially when most bookless games between top engines are already drawn. Fritz had drawn both Leela and Komodo Dragon in the WCCC (Stockfish did not play), before winning the title by drawing an Armageddon game against Komodo Dragon.
The differences in the format meant there were questions around how well Fritz would perform in the TCEC. The division started out very close, with most engines in with a chance for both promotion and relegation. As the division proceeded, Fritz eventually secured a promotion spot. It finished with 26.5/44, comfortably ahead of its closest rivals last season, Halogen (21.5/44) & ClassicAra (which did not promote out of QL). It certainly looks like Fritz has gained a lot of strength in the past few months! It was not however able to catch Minic, which led from start to finish in spite of two lost openings to Halogen and Weiss. Long-time competitor Arasan finished second, losing only one opening to Minic. The last promotion slot was hotly contested. In the final round, Nemorino needed to beat BlackMarlin with the White pieces. The opening, a Benoni, gave Nemorino a solid chance of victory. BlackMarlin went for the complicated 10…Ne5, a move the kibitzing Leela was very skeptical of. After BlackMarlin further sacrificed a piece for two pawns, Leela signalled a nearly-winning (by Leela standards) +1.13. Unfortunately for Nemorino, a couple of inaccuracies gave away most of its advantage. While it kept the material and even won another pawn, BlackMarlin had a menacing pawn phalanx, capped by a protected passed pawn on c3. With the finishing line in sight, BlackMarlin went for 36…c2?, allowing Nemorino’s King to advance. Nemorino eventually converted to seize the final promotion spot.
Next up is a stacked League 1. The four promoting engines join a league with several former Premier Division engines, as well as other engines that have only narrowly missed out on promotion in the past. All eight of these engines will be playing with an update as well. With only two promotion spots available, the league promises to be unpredictable. Catch all live games at https://tcec-chess.com/.
Article by Low