Everything on this page is free. Between them, these three cover what a club player actually needs at home: an engine to tell you where you went wrong, somewhere to keep your games, and something to play against that feels human.
Stockfish — the engine
Stockfish is the strongest chess engine in the world and it costs nothing. It is open source, and it has been comfortably stronger than any human player for years, so when it tells you a move was a mistake, it was a mistake.
On a phone or tablet you want an app with Stockfish already built in — Droidfish on Android, or one of the several Stockfish apps on iOS. On a computer, Stockfish on its own is just an engine with no board: you need a program to drive it, which is what Scid vs PC below is for.
Download it from stockfishchess.org.
Scid vs PC — your own game database
Scid vs PC gives you a board, a database of your games, and a place to plug Stockfish in. Once it is set up you can play through a league game you lost, let the engine annotate it, and see exactly which move turned it.
Download it from scidvspc.sourceforge.net. It runs on Windows, Mac and Linux.
Setting it up with Stockfish
- Install Scid vs PC, and download Stockfish separately.
- In Scid vs PC, go to Tools → Analysis Engines and add Stockfish, pointing it at the file you downloaded.
- If you have an opening book file, unzip it somewhere sensible and tell Scid where it is under Options → Books Directory.
Getting a game analysed
- Open your game with File → Open. Most clubs and online sites will give you the game as a PGN file.
- Start the engine with F1, or Tools → Start Engine 1.
- Select the Stockfish tab and press the annotate button.
- Set the analysis depth — 20 is a sensible minimum. Deeper means slower.
- Let it run, then play through the game and read what it says.
A word of encouragement: the engine will be rude about your game. It is rude about grandmaster games too. What matters is not the number of question marks but the two or three moments where the evaluation swung, and understanding why.
Leela Chess Zero — an engine that plays like a person
Stockfish calculates. Leela Chess Zero learned chess by playing itself millions of times, in the same way DeepMind's programs learned Go, and the result plays in a way a human can follow. Its suggestions tend to be moves you could imagine a strong player choosing, rather than a computer line nobody would ever find.
The easiest way to meet it is to play one of the Leela bots on Lichess. If you want it on your own machine, start at the Leela Chess Zero site; you can download different strength networks to get a game rather than a hiding.