Free online Chess server. Play Chess now in a clean interface. No registration, no ads, no plugin required. Play Chess with the computer, friends or random opponents.
Create a game Tournament Simultaneous exhibitions
Chess basics Puzzles Practice Coordinates Study Coaches
Lichess TV Current games Streamers Broadcasts (beta) Video library
Players Teams Forum Questions & Answers
Analysis board Opening explorer Board editor Import game Advanced search
Sign in

Stockfish is learning

Thibault Announcements

Artificial intelligence for Atomic, Horde, and Racing Kings!

You may know about Stockfish, the strongest chess player in the known universe. It's a fantastic chess artificial intelligence, and like all the greatest programs, it's open source and actively maintained by enthusiasts (yes just like lichess :)

Naturally we use it on lichess:

  • Play against the computer, it's Stockfish with 0.4s per move, running on our servers.
  • Request a computer analysis, it's Stockfish with 3.5 million nodes per move (about 4 CPU seconds per move), running on our servers.
  • Use local analysis, it's Stockfish again, this time running in your browser, up to depth 18.

Out of the box, Stockfish only plays standard chess, and Chess960. But since it's open source, can we teach it more variants?

Turns out, we can!

Toadofsky has been working on it for a while, and successfuly taught Stockfish how to play King Of The Hill and Threecheck. As a result, we've been able to play the machine in these variants, as well as get computer analysis for our games!

But that was only the beginning. Recently, ubdip joined the Stockfish development team to help Toadofsky and, together, they achieved this amazing feat:

Make Stockfish play Atomic Chess AND Horde Chess AND Racing Kings.

Yes. You can now play all these variants against the machine. You can request server computer analysis. You can use local analysis.

Do you think it's crazy?

Wait, that's not all. We also offer an opening explorer for all these variants!

Built by revoof, the opening explorer continually feeds on the games you play on lichess, and goes 50 plies deep.

Welcome to 2016, the year when you can analyse an Atomic chess game with computer support and opening explorer. For free, and in style.

Isn't it amazing, what the chess community can achieve?