TCEC S23 Sufi, CCC19 Rapid : Both Underway

'Another two weeks, another report about the world's top two ongoing engine vs.engine competitions.' That's what the lead sentence for this post should say, except that it's been three weeks since the previous report. My wife frequently insists on taking vacations that interfere with all of my well-planned schedules. That previous report, TCEC S23 DivP, CCC19 Blitz Final : 'Well' Underway (October 2022), can be summarized as follows:-

TCEC: S23 DivP is well underway. Stockfish is two points ahead of LCzero and KomodoDragon, which are separated by a half-point. • CCC: Stockfish won 'CCC19 Blitz Main' ahead of LC0 and Dragon, who were well ahead of the other seven engines. In the 'CCC19 Blitz Challenger Match', Dragon beat LC0 by six points in a 300 game match. Stockfish is pummelling Dragon in the 'CCC19 Blitz Final' match.

You might guess that a three-week interlude would mean more to report than the normal two-week interlude, and you would be right. The following summary brings us up-to-date to the current situation.

TCEC: In S23 Premier Division (DivP) Stockfish won all of its mini-matches, finishing three points ahead of LCzero and KomodoDragon. Those habitual contenders for 2nd/3rd place in all recent engine events tied, but were still well ahead of the other five engines. How did TCEC break the tie to determine Stockfish's final opponent? The first tiebreak rule said,

1. In case of engines being tied, then the direct encounter(s) between the tied engines decides first.

The two engines finished +2-2=4 in their individual mini-match. The second tiebreak rule said,

2. The Sonneborn-Berger [S-B] is the second criterion.

LCZero had S-B tiebreak considerably superior to KomodoDragon. The difference appears to be due to LCZero's much better performance against Stockfish, 'minus one' versus KomodoDragon's 'minus four'.

The Dragon then played a consolation 'Infrafinal' match against Ethereal, the engine that finished clear fourth (although with an even score) in DivP. KomodoDragon won the 100-game match by 19 points.

The 100-game S23 final match (aka 'Superfinal' or 'Sufi' in TCEC jargon) has seen five of the games finish, with Stockfish having a one point lead over LCZero. For the result of the previous Sufi, see TCEC S22, the Fish Again; CCC17 Bullet Top-3 (April 2022; 'the Fish's fifth straight Sufi victory').

CCC: In the 'CCC19 Blitz Final' 300-game match, Stockfish beat Dragon by 60 points. After a few exhibition events, including two in an 'OpenBench Interlude' series, the site launched a 'CCC19 Rapid' multi-stage event.

Eight engines competed in the 'CCC19 Rapid Newcomers' stage, with the top four promoting to the eight-engine 'Qualifier #1'. Those promoted engines finished in the last four places, so four different engines promoted to the eight-engine 'Qualifier #2'. Those four engines are currently occupying the last four places. The next stage should be the 'Main' event.

[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. • NB: Leela = LC0 = LCzero; Dragon = KomodoDragon]