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Stockfish Strikes Back, Tops Lc0 In Computer Chess Championship
Stockfish reclaimed its Computer Chess Championship title from the Lc0 neural network engine.

Stockfish Strikes Back, Tops Lc0 In Computer Chess Championship

Pete
| 62 | Chess.com News

In a thrilling battle that came down to the final games, Stockfish won the Chess.com Computer Chess Championship this week, edging out the machine-learning engine Lc0.

Stockfish scored 82.5/150 to reclaim its championship title and top Lc0, which came in at 81 points. Lc0 had won the last Computer Chess Championship in a historic performance.

The neural-network engine Leelenstein was third with 76/150, and Houdini trailed far behind in fourth at 60.5 points in the CCC 8: Deep Dive finals. 

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.

ccc 8 deep dive

You can vote on each game and follow the always-running Computer Chess Championship:

The four finalists will join a field of 18 total chess engines for the next event, CCC 9: The Gauntlet, which will begin after the CCC 8 bonus games (live now).

CCC 9 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.

ccc 9 the gauntlet

CCC 9: The Gauntlet Information:

  • Engines: 18
  • Stages: 4
  • Games: 2,090
  • Estimated duration: 30 days

CCC 9 Stage 1:

  • Format: 5x round-robin
  • Engines: 12
  • Games: 660
  • Time control: 5+2
  • Opening book: yes
  • Endgame adjudication: bullet mode only
  • Engine list:
    • 1. Stockfish
    • 2. Lc0
    • 3. Allie
    • 4. Laser
    • 5. Xiphos
    • 6. Andscacs
    • 7. Dark Queen Lc0
    • 8. Rofchade
    • 9. Wasp
    • 10. Rubichess
    • 11. Winter
    • 12. Stoofvlees

CCC 9 Stage 2:

  • Format: 7x round-robin
  • Engines: 10
  • Games: 630
  • Time control: 5+2
  • Opening book: yes
  • Endgame adjudication: bullet mode only
  • Engine list:
    • 1. Stockfish (Automatic)
    • 2. Lc0 (Automatic)
    • 3. Leelenstein (Automatic)
    • 4. Komodo Monte Carlo (Automatic)
    • 5. Ethereal (Automatic)
    • 6. Fire (Automatic)
    • 7-10. Qualifiers from previous stage

CCC 9 Stage 3:

  • Format: 20x round-robin
  • Engines: 6
  • Games: 600
  • Time control: 5+2
  • Opening book: yes
  • Endgame adjudication: bullet mode only
  • Engine list:
    • 1. Stockfish (Automatic)
    • 2. Lc0 (Automatic)
    • 3. Komodo (Automatic)
    • 4. Houdini (Automatic)
    • 5-6. Qualifiers from previous stage

CCC 9 Stage 4 (finals):

  • Format: 100x round-robin
  • Engines: 2
  • Games: 200
  • Time control: 10+5
  • Opening book: yes
  • Endgame adjudication: bullet mode only
  • Engine list:
    • 1. Qualifier from previous stage
    • 2. Qualifier from previous stage

CCC 8: Deep Dive Crosstable:

CCC 8 Finals Crosstable. Click on the image for a larger version.
CCC 8 Finals Crosstable. Click on the image for a larger version.

CCC 8: Finals PGN Download and Selected Games:

Stockfish built up deadly pressure with passed pawns and open files. It was too much for Houdini, which had to allow the vicious fish to establish two rooks on the seventh rank, with checkmate quickly to follow.

Lc0 outplayed its machine-learning relative Leelenstein with many classic neural-network strategies, including the "fawn pawn" on the h-file, and bringing all of its pieces into action to force an easily winning king-and-pawn endgame.

Of course, it wouldn't be a classic Lc0 game without three completely unnecessary under-promotions and a troll-like queen sacrifice as Lc0 toyed with its opponent before delivering mate.

 Follow the always-running Computer Chess Championship:

Can Stockfish defend its title in the new format of Computer Chess Championship? How will the new engines do in "the gauntlet"? Let us know in the comments, and be sure to vote on the games at the CCC main site. 

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