Leela Wins TCEC S15; Stockfish Wins CCC8 Finals

In last week's post, TCEC S15 and CCC8 Finals Both Underway, we left our two major engine-vs-engine competitions in full swing. To summarize that post:-

TCEC: With just over half of the S15 superfinal games played, Leela leads Stockfish by 27.5-24.5 (+8-5=40). • CCC: In the final stage, with about two-thirds of the games already played, the order of the four engines is Stockfish, Leela, Leelenstein, Houdini. The point spread between each successive place is almost enough to guarantee that this will be the final standing.

In the meantime, both competitions crystallized around clear winners.

TCEC: It ain't over 'til it's over, but the S15 superfinal is effectively over. Leela leads Stockfish by seven games with six games still to be played; the current score is +14-7=73. It's been more than three months since S14 ended, which I documented in Stockfish Wins TCEC S14; CCC6 S2 Underway (February 2019; also links to TCEC winners for S10-S13): 'the final score +10-9=81 in Stockfish's favor'. Last month, in TCEC S15 DivP Underway; Leela Wins CCC7 Final (April 2019), I commented,

CCC7 marked the symbolic end of the dominance of the traditional, handcrafted, alpha-beta engines. The passing of the baton to a new generation needs to be confirmed by a TCEC victory for an AI/NN engine, but that is a question of 'when', not 'if'.

The baton has now been passed. For future TCEC/CCC competitions, I expect that more AI/NN engines will join the race and that the alpha-beta engines will struggle to maintain the pace.

CCC: CCC8 finished in the order predicted last week: Stockfish, Leela, etc. A final report on the event, Stockfish Strikes Back, Tops Lc0 In Computer Chess Championship (chess.com), said,

Lc0 defeated Stockfish in their head-to-head match, four wins to three. Lc0 also won its head-to-head matches with the other two finalists. But Stockfish performed better in the four-engine round-robin to take back the title by beating up on the two weaker engines.

The Chess.com report continued,

The four finalists will join a field of 18 total chess engines for the next event, CCC9: The Gauntlet, which will begin after the CCC8 bonus games (live now). CCC9 will try a new format with four stages of increasingly powerful engines. Strong engines will be seeded into stages two and three, but will still play in the preliminary rounds to challenge a varied field, including some new entrants to the Computer Chess Championship.

In the meantime, the CCC8 Bonus also finished, won by Brainfish. The following chart shows the final crosstables for the two CCC8 events that finished during the past week.

Top: CCC8 Final; Bottom: CCC8 Bonus

In next week's post I expect we'll have news about TCEC S16 and more details about CCC9. Since we're at a transition point for both competitions, it's a good time to decide whether I want to continue these weekly reports.

[For further information from the various stakeholders in the engine-to-engine events, see the tab 'TCEC/CCC Links' at the top of this page. • Leela = LC0 = LCzero]