Chess Terms
Stockfish

Stockfish

The most powerful chess engines of all time are all well-known to most chess players. If you are wondering which available engine is the strongest, then look no further—Stockfish is the king of chess engines. 

Let's learn more about this mighty engine. Here is what you need to know about Stockfish:


What Is Stockfish?

Stockfish is the strongest chess engine available to the public and has been for a considerable amount of time. It is a free open-source engine that is currently developed by an entire community. Stockfish was based on a chess engine created by Tord Romstad in 2004 that was developed further by Marco Costalba in 2008. Joona Kiiski and Gary Linscott are also considered founders.

Stockfish is not only the most powerful available chess engine but is also extremely accessible. It is readily available on many platforms, including Windows, Mac OS X, Linux, iOS, and Android.

stockfish chess engine
Stockfish logo. Image: Stockfishchess.org.

Stockfish's accomplishments are more impressive than those of any other chess engine. It has won eight Top Chess Engine Championships (TCEC) through 2020. Stockfish has also dominated Chess.com's Computer Chess Championship since 2018, winning the first six events and more. 

Stockfish had firmly established itself as the strongest chess engine in the world before 2017, which is why the chess world was shaken to its core when it lost a one-sided match to a neural network computer program called AlphaZero. This loss to AlphaZero led to the development of other neural network projects (most notably Leela Chess Zero, Leelenstein, and Alliestein).

Although Stockfish has kept its spot atop the chess engine list, the neural network engines had been getting closer and closer to Stockfish's strength. In September 2020, Stockfish 12 was released, and it was announced that Stockfish had absorbed the Stockfish+NNUE project (NNUE stands for Efficiently Updatable Neural Network). What does this move mean? Well, now the raw power of the traditional brute-force Stockfish has been improved by the evaluation abilities of a neural network engine—a mind-boggling combination!

stockfish chess
Stockfish 12 has added neural network evaluation abilities.

As of October 2020, Stockfish is the highest-rated engine according to the computer chess rating list (CCRL) with a rating of 3514—it is the only engine with a rating above 3500. According to the July 2020 Swedish Chess Computer Association (SSDF) rating list, Stockfish 9 is ranked #3, Stockfish 10 is ranked #2, and Stockfish 11 is ranked #1 with a rating of 3558. Taking the top three spots with three different versions is quite impressive.

According to this great video on the strongest chess engines of all time (based on the SSDF rating lists), Stockfish is the strongest engine of all time—a sentiment that is widely shared in the chess community.



Stockfish Accomplishments

As mentioned, Stockfish has dominated the TCEC since it started participating. It has won eight TCEC championships and also has six second-place finishes—it has placed first or second in every season it has participated since 2013 with only one exception. From 2018-2020 it won seven out of nine TCEC seasons ahead of Komodo, Leela Chess Zero, Shredder, Houdini, and other top-level engines.

Stockfish also won the 2014 TCEC Fischer Random tournament, the TCEC season 10 Rapid tournament, and three TCEC cups (in 2018, 2019, and 2020 respectively).

stockfish chess
Stockfish has dominated the Chess.com computer chess championships.

Chess.com's Computer Chess Championship has also been a common winning ground for Stockfish. It has won eight of the 13 events through 2020 and placed second in four others. Stockfish continues to defeat the neural network engines in most competitions.

Stockfish Games

The first game example is from the 2018 Stockfish-AlphaZero match. Stockfish wins quickly and easily—can you ask for more than defeating the strongest chess entity that the world has ever seen in a mere 22 moves? Stockfish sacrifices a pawn early in the opening and gains a large advantage after 13. Rd3. After 18. Rh4, all of Stockfish's pieces are active and developed, while all of AlphaZero's pieces are on the back rank (except for the queen):

Stockfish chess
All of Stockfish's pieces are active and developed after 18. Rh4.

The sacrifices with 19. Bc4! and 20. Nce4! are powerful and finish the game quickly.

Stockfish chess
The Stockfish-AlphaZero clash changed the entire chess engine scene.

In this second game example, we see Stockfish dispatch another famous chess engine that stood atop the chess engine world for years: Rybka. Stockfish gains a nice advantage out of the opening that it keeps throughout the game. The fireworks start with Stockfish's 28. Bxh6+!

Stockfish chess engine
Stockfish tears open Rybka's kingside with 28. Bxh6!

Stockfish keeps up the pressure with an exchange sacrifice on move 31 and dominates the rest of the game after Rybka's 33...Kh7:

In this fantastic video by Chess.com's NM Sam Copeland, Stockfish+NNUE dismantles the neural network engine Stoofvlees:

How To Analyze With Stockfish On Chess.com

Stockfish is the engine for analysis on Chess.com. It is very easy to use on this site in several ways. One is to go to Chess.com/analysis and load your PGN or FEN:

Stockfish chess
You can access Stockfish on Chess.com by going to Chess.com/analysis.

Another easy-to-use method of analyzing your games on Chess.com with Stockfish is to select "Analyze" after you complete a game in Live Chess.

Stockfish chess engine
After you complete a live game on Chess.com, you can select "Analyze" and review your game with Stockfish.

Yet another way to analyze your games with Stockfish on Chess.com is with Chess.com's analysis board. Simply go to Live Chess and select the drop-down menu below the Tournaments tab:

Stockfish chess engine
Select the drop-down menu under the Tournaments tab.

After you select this menu, simply press "Analysis Board." Then you can analyze with Stockfish!

Stockfish chess.com
Select "Analysis Board" to analyze with Stockfish on Chess.com.

The Analysis Board is very easy to use and can help you with any phase of the game. This article explains how to use it.

Stockfish chess.com
Chess.com's Analysis Board using Stockfish.

In this video, Chess.com's IM Danny Rensch explains some of the Stockfish analysis features available on Chess.com:

Conclusion

You now know what Stockfish is, why it is important, how to analyze with Stockfish on Chess.com, and more. Head over to Chess.com/CCC to watch Stockfish and other top engines battling at any time on any day!