[CCC] Classical Cup #2

Update: Stockfish has won the CCC Classical Cup #2, with a score of 9.5/16.0, in a head-to-head matchup against Leela.

After a clear win for Stockfish against both Leela and Torch in the CCC22 Rapid series, it is time to return to another Classical event. The 2nd Classical Cup will once again featuring the top-8 engines from CCC22 Rapid, competing in a double-elimination bracket in sets of 16 30+5 classical games, up from 10 games in the 1st iteration of the CCC Classical Cup.

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This event will be run as a series of 16-game matches (due to technical limitations). If one player scores 8.5 points before the conclusion of the match, the remaining games may continue to be played. If the engines are still tied after the 16 games, additional 16-game matches will be played at gradually reduced time controls. Those time controls will be 10+3 (Rapid), 3+2 (Blitz), and finally 1+1 (Bullet). The Bullet event will repeat until a winner is determined.

The top-6 seeds come directly from the CCC22 Rapid: Semifinals event. Those engines are: Stockfish, Leela, Torch, Dragon, Berserk, and Caissa. The remaining 2 seeds come from the 7th and 8th place spots in the CCC22 Rapid: Main. Those engines are: Ethereal, and Rubi.

The openings will be selected from the same book as before, Stefan Pohl's UHO 2022 book. A new book will be used starting in the CCC23 series of events, as well as for a 3rd iteration of the classical cup.

For newer watchers, opening books are used to ensure that engines do not draw every game. If allowed to play from the starting position, draws would be ubiquitous. In order to remedy this, unbalanced openings are chosen, where one side (typically White) has an advantage. In order to maintain fairness, the engines will play a game-pair. In one game they will play the advantaged side, hoping for a win. In the next game they will play the disadvantaged side, hoping to maintain a draw.

Below is a list of the pairings and match numbers for each round. This will be updated as the event runs, providing a link to the games, and a recap of the score. The bracket at the start of this post will also be updated frequently during the event. Matches may, at the discretion of the Tournament Director, be played out-of-order as needed to allow engine authors and teams sufficient time to provide updates if desired.

First Round Pairings:

• 1. Stockfish vs Rubi (11.0-5.0)
• 2. Berserk vs Dragon (7.5-8.5)
• 3. Torch vs Caissa (10.0-6.0)
• 4. Ethereal vs Leela (11.0-5.0)

First Round Losers Pairings:

• 5. Rubi vs Berserk (8.0-8.0) and Tie Breaker #1 (6.0-10.0)
• 6. Caissa vs Ethereal (8.0-8.0) and Tie Breaker #2 (8.5-7.5)

Second Round Pairings:

• 7. Stockfish vs Dragon (10.0-6.0)
• 8. Torch vs Leela (8.0-8.0) and Tie Breaker #3 (6.0-10.0)

Second Round Losers Pairings:

• 9. Torch vs Berserk (9.0-7.0)
• 10. Dragon vs Caissa (8.5-7.5)

Third Round All Pairings:

• 11. Stockfish vs Leela (8.5-7.5)
• 12. Torch vs Dragon (9.0-7.0)

Remaining Pairings:

• 13. Leela vs Torch (9.5-6.5)
• 14. Stockfish vs Leela (9.5-6.5)