Chess Engine

Chess Engine

It's 1997, and the world watches in disbelief as GM Garry Kasparov, arguably the best chess player in history, loses a match against a computer. The era of chess engines has started, changing the game's landscape forever.

Here is what you need to know about chess engines:


What Is A Chess Engine?

A chess engine is a computer program that analyzes chess positions and returns what it calculates to be the best move options. If computers were chess players, engines would be their brains. Chess.com, for instance, allows users to play against computer personalities using the Komodo engine and uses Stockfish in the Analysis Board.

Chess engine.
Chess.com uses Komodo on the Computer Play page.

Chess engines are much stronger than humans, with the best of them reaching an estimated Elo rating of more than 3000. Engines are also getting stronger each year due to improvements in hardware and software. AlphaZero, for instance, introduced the concept of neural networks to the chess world. All the most potent engines have adopted this kind of information processing tool and become even more powerful.

Here is a video of the strongest computer chess engines over time:

Most Popular Chess Engines

Many chess engines are available, but only a few of them continuously appear on the top ranks of computer championships. Here is a list of the most popular engines.

AlphaZero

AlphaZero was developed by DeepMind, an artificial intelligence and research company that was later acquired by Google. It was the first engine to use reinforcement learning and self-play to train its neural networks.

AlphaZero shocked the world after easily defeating Stockfish—the strongest engine at the time—in a 100-game match.

AlphaZero chess engine.
DeepMind logo. Image: deepmind.com.

Stockfish

Stockfish is currently the strongest chess engine available to the public. As an open-source engine, an entire community of people is helping to develop and improve it. Like many others, Stockfish has included neural networks in its code to make even better evaluations of chess positions.

Stockfish is available to the public on all major platforms like Windows, Mac OS X, Linux, iOS, and Android.

Stockfish chess engine.
Stockfish logo. Image: stockfish.com.

Here's a video of NM Sam Copeland going over a gorgeous victory by Stockfish NNUE (now incorporated into Stockfish) over none other than Leela Chess Zero.

Leela Chess Zero

Leela Chess Zero is currently the second strongest publicly available chess engine. The engine (which also goes by the names Lc0, LCZero, and Leela) is part of an open-source neural network project started in 2018.

Lc0 is inspired by DeepMind's AlphaZero project and has learned the game through reinforcement learning and repeated self-play.

Leela Chess Zero chess engine.
Leela Chess Zero logo. Image: lczero.org.

Here's a video of IM Danny Rensch analyzing one of Leela's masterpieces:

Komodo Chess

Komodo is one of the dominant and most successful Universal Chess Interface chess engines on the market. Don Dailey developed it in 2010, and Mark Lefler kept working on it in 2013. The engine also has counted on the support of GM Larry Kaufmann for many years to improve its playing skills.

Komodo chess engine.
Komodo's Dragon engine logo. Image: komodochess.com.

Chess.com acquired Komodo in 2018 and uses it on our Play Computer page. The engine's ability to run at different playing strengths, with different styles and opening books, has made it a popular choice among players.

Give Komodo a go and try playing against one of its different personalities available here on Chess.com!

Komodo chess engine.
Play different bot personalities on Chess.com, including chess celebrities and Beth Harmon!

Deep Blue

Deep Blue was a chess computer created by IBM as part of a publicity stunt. The company wanted to display its computer's processing power and arranged a match against Kasparov, the world champion at the time.

Deep Blue played two matches against Kasparov, one in 1996 and another in 1997. Deep Blue lost the first match but defeated the world champion the next year, causing an uproar of mixed emotions. While many people marveled at the power of technology, it was the first time a computer ever put human superiority over machines in check.

Deep Blue
One of the Deep Blue racks on display at the Computer History Museum. Photo: James, CC.

Shredder Chess

Shredder is a commercial chess engine that can be purchased by anyone. Stefan Meyer-Kahlen created the engine and user interface in Germany in 1993.

Shredder is available on multiple platforms, like Windows, Mac OS, Linux, Android, iOS, and even on Amazon Kindle.

Shredder chess engine.
Shredder Chess logo. Image: shredderchess.com.

Fritz

Fritz, another commercial chess program, was developed by Frans Morsch and added to ChessBase in 1991. Like most others on this list, Fritz has won many Computer Chess Championship titles over the years.

Fritz is available on Windows and multiple other platforms. Since 2009, the engine has also been available for some consoles like Nintendo Wii, Nintendo DS, and Sony Playstation 3.

Fritz chess engine.
Fritz logo. Image: fritz.chessbase.com.

Rybka

Rybka is another commercial chess engine. Developed by IM Vasik Rajlich in the early 2000s, it has partnered with ChessBase.

This engine sparked some controversy when the International Computer Games Association (ICGA) claimed that Rybka plagiarized its code. However, the FIDE Ethics Commission concluded in 2015 that those claims were false.

Rybka chess engine.
Rybka's logo for the 2018 Computer Chess Championship. Image: Chess.com.

Houdini Chess

Houdini is a commercial chess engine developed by the Belgian chess player and programmer Robert Houdar in 2010. At the end of 2019, Houdini appeared as the highest-rated commercial engine in the world (only behind Stockfish, Leela Chess Zero, and Komodo).

Houdini is not as accessible as other engines since it's available for only Windows.

Houdini chess engine.
Houdini's logo for the 2018 Computer Chess Championship. Image: Chess.com.

HIARCS

HIARCS (an acronym for Higher Intelligence Auto-Response Chess System) is a proprietary chess engine developed by Mark Uniacke in 1980. It is the oldest chess engine among those that have reached more than 3000 Elo rating points.

HIARCS is available for Windows and Mac OS.

Conclusion

You now know what a chess engine is, which engines are the strongest, and how to play one of the best chess engines on Chess.com. Head over to Chess.com/CCC to watch top chess engines competing against each other at any time and day!

The Computer Chess Championship on Chess.com.
The Computer Chess Championship is always live on Chess.com.