Stockfish Wins Computer Chess Championship Bullet; 'Escalation' Next

Stockfish added another Computer Chess Championship to its trophy rack, emerging as the winner of CCC 4: Bullet Brawl. The champion engine remains the winner of all Chess.com computer events, and now can claim dominance in the fastest time control yet.

Follow the always-running Computer Chess Championship:

• Watch and chat on Chess.com/CCC—includes the all new Chess.com user interface
• Watch and chat on Twitch.tv/computerchess—includes AI-generated background music

Stockfish scored 97/140 to take the gold medal in the event, which was played at a time control of one minute plus a two-second increment. The machine-learning Lc0 engine continued its ascendance to the peak of computer chess with a second-place performance on 91 points.

Lc0 also managed the impressive feat of scoring dead even with Stockfish head-to-head in the tournament, at +3 -3 = 14 in their 20 games together. Lc0 was the only engine to score a win against Stockfish in the event.

These two engines began a 100-game bonus match, in progress now, which at press time Stockfish was leading comfortably at 35.5/66. You can watch the bonus match at the CCC official site.

The Houdini engine was far back in third place in the bullet championship, at 82/140, and Komodo earned fourth with 76.5 points.

CCC 4 crosstable:

Sample games and PGN:

Stockfish is the current king of the computer chess world, but it sometimes struggles against neural-network engines like AlphaZero, Lc0 and now "Antifish," which is a version of Lc0 trained specifically to beat Stockfish.

This game was played in a CCC bullet bonus event before the main tournament started (Stockfish went on to win the match). Here, Stockfish rates itself as having a solid advantage from moves 15-21, but that evaluation evaporates before its fishy eyes and the game is lost.

Before neural network engines came along, Stockfish losing a self-proclaimed advantage and losing the game simply never happened.

Despite its three losses to Lc0 in CCC 4, Stockfish won the tournament easily, and did not drop a single game against any other opponent.

Here Stockfish shows its trademark blend of tactical expertise and positional mastery as it obliterates Komodo with a phalanx of advancing queenside pawns that is probably still giving the lizard cold-blooded nightmares.

• Download the full CCC 4 PGN here
• Download the Stockfish vs Antifish bullet PGN here
• Download the Stockfish vs Antifish bonus crosstable here
• Download the Stockfish vs Lc0 bonus match PGN here 

CCC 5: Escalation:

Next up for the Computer Chess Championship is another blitz tournament with a twist to the usual round-robin format. The engines will still play a round robin, but the order of the games will ascend by seed so that the higher seeds will play their games last.

CCC 5: Escalation is a 10-engine blitz tournament with a time control of 10 minutes plus a five-second increment. It is an eight-times round-robin with 360 games in round one. The top two engines will play a 100-game finals afterwards.

The format, named escalation, begins with a matchup between the #10 and #9 seeds. The tournament proceeds with each engine playing its matches against all lower-seeded engines until a higher engine is introduced. The matches escalate until the top engines are playing one another.

The end of the escalation will feature the eight games between the top two seeds, Stockfish and Lc0, which will be the first time they meet all tournament. In the escalation format, each game gets more and more important as the stronger engines make their mark on the standings.

• Click here for a full schedule of all 360 games of CCC 5: round one. 

The full specifications of CCC 5 are below:

• 10 engines
• Escalation order
• 10 + 5 time control
• 8xRR
• 360 games in round one
• 100-game finals with the top two engines from round one
• Expected duration of round one: seven days
• Adjudication: 50-move rule, repetition, and insufficient material draws. TB draws. No eval adjudication, "speed up" one-sided games
• Endgame tablebases on, including 7-man TB where supported
• No opening book

The full list and seeding of CCC 5 participants:

1. Stockfish
2. Lc0
3. Houdini
4. Komodo
5. Fire
6. Ethereal
7. Komodo MC
8. Shredder
9. Xiphos
10. Lc0 (dev)—update: Lc0-dev will automatically update itself to the strongest available network file before each game.

CCC 5: Escalation will begin after the CCC 4 bonus games are completed.

Watch the always-running Computer Chess Championship:

• Watch and chat on Chess.com/CCC—includes the all new Chess.com user interface
• Watch and chat on Twitch.tv/computerchess—includes AI-generated background music