Play chess against twenty characters from absolute beginner (200) all the way to raw Stockfish (3600+), each with their own personality, strengths, and weaknesses, twelve of them thinking with real neural networks (Maia and Leela Chess Zero), plus a built-in coach: timed hints, assisted analysis that colors your candidate squares, mistake and blunder warnings before you commit a move, and a post-game grandmaster report. Train with your personal blunder deck (spaced repetition, tagged by tactical theme), an opening repertoire trainer, an endgame gym, guess-the-move on classic games, a personal opening tree, themed and odds sparring, a career ladder, and a full analysis board with position setup and a plan coach that names the opening, says what each side is playing for, and prices 88 named checkmates, attacking schemes, positional ideas, and endgame techniques against the engine. Runs entirely in your browser.
🏆 Sign in to save your progress:Optional. Saves your last 10 games (with PGN), blunder deck, and repertoire to your account, so they follow you to another device. Skip it to stay fully local. No email or personal details are stored.
Playing online as Your progress is tied to your account. Sign in on another device to bring it with you. Sign out from the menu at the top of the page.
Choose your opponent
Henry · 1450 Elo
Club veteran. Slow, steady, and grumpy about modern chess.
💪 Strengths: Endgame grinder; wins rook endings a pawn down on stubbornness.
⚠️ Weaknesses: Modern opening fashion. "In my day we played 1.e4 and meant it."
♟️ Playing since: Age 41. Twenty years, all in the same club chair.
💼 Off the board: Watchmaker. Distrusts anything with a battery, including online chess.
🎲 Fun fact: Keeps score in a paper scorebook. Refuses pencils that have erasers.
🎭 Style: Solid: prefers trades, castling, and tidy positions over adventure.
🧠 Brain: Maia 1400, a neural network trained on millions of human games at this rating, running in your browser
Your color
Time control
Coach
Bot pace
Board
Downloading Stockfish (~7 MB). Characters rated 1150–2500 also fetch their neural-network brain (3–13 MB) the first time you meet them. Everything runs in your browser; nothing is sent to a server.
Your progress
Stored in this browser. Join the leaderboard above to also keep your last 10 games online.
Blunder deck
Every mistake and blunder from your games becomes a puzzle: find the move you missed. Positions return on a spaced schedule (1, 3, 7, 16, 35, 70 days), sooner when you miss them again. Each puzzle is tagged with its tactical theme.
Endgame gym
Classic endgames against full-strength Stockfish. It defends and punishes perfectly, so a pass here means you really own the technique.
Memory gym
Look at a position, then rebuild it from memory, spot what changed, or answer questions about it. Positions come from your own games and the classics, never random scatter, so you train yourself to see chess patterns instead of dots. 100 stages from 4 pieces to a full board; look time scales with the piece count and shrinks as you climb, and you can always hide the pieces early when you are ready.
Pairs
The classic memory game, chess flavored. Flip two cards; a match stays up, a miss turns back over. Fewer attempts earn more stars, and each flavor teaches something real: pieces, coordinates, moves, values, mating patterns, openings, and the great players.
Sparring
Themed games start from a chosen opening and count as normal games. In odds games the selected opponent starts without a piece; those are casual and stay out of your record.
Career ladder
Guess the move
Replay a classic game, or one of your own, and predict every move for one side. 3 points for the game move; Stockfish scores your alternatives. Each tile keeps your best finished score: green from 75%, red below 33%, yellow in between.
A self paced course on the imbalances, the differences that decide what a position is about and what to do in it. Each lesson gives you a position, a short read, and exercises answered on the board, and turns green when you finish it.
Opening repertoire
Record your opening lines by playing both sides on the board, then drill them from memory on the same spaced schedule as the blunder deck.
Your opening tree
Built from your saved games. Click a move to follow the branch; the score bar shows your results, and ⚠ marks branches where they start dropping.
Analysis board
Free analysis with the full engine: top three lines live, move pieces for either side, set up any position, and play it out against the selected opponent.
Leaderboard
Coach is checking your move…
A
15:00
15:00
Position controls
Position
Saved positions 0/6Saved in this browser
Continue and review
Engine and board
WhiteBlackdeeper color means a wider margin
Load a position or game
Fair play review
Player ratings
or drop .pgn files here
Castling rights
Pick a piece, then click squares to place it. Pick the ✕ to erase. Both kings are required.
Hints and statslive engine forecast
Position status
Coach0.0
Make your move. If you think for a while, I will point you in the right direction.
Move history
Predicted continuationsconditional replies from the current engine line
Plans and patterns
Pick a goal
Every plan here is read off the board. Pick one and the board keeps score of how far along it you are; the engine only speaks when you ask it what the plan costs.
Powered by Stockfish (GPLv3, via
stockfish.js) and
chess.js.
Characters rated 1150–1900 think with Maia
neural networks (CSSLab, University of Toronto, GPLv3); 2000–2500 with a
Leela Chess Zero T70 network (GPLv3),
both via ONNX Runtime Web (MIT).
Piece images by Colin M.L. Burnett (CC BY-SA 3.0). The engine and coach run locally in your browser;
the optional leaderboard stores only your chosen name, last 10 games, and blunder-deck positions online.
The crowd book shares anonymous position evaluations (position, depth, eval) between visitors.