Hossein’s Notes
  • Math
    • Overview
    • Linear Algebra
    • Calculus
    • Probability
    • Statistics
  • Machine Learning
    • Overview
    • Supervised Machine Learning: Regression and Classification
    • Advanced Learning Algorithms
    • Unsupervised Learning, Recommenders, Reinforcement Learning
  • Deep Learning
    • Overview
    • Neural Networks and Deep Learning
  • Agentic AI
    • Overview
    • Frameworks
    • Agent Architecture
    • Async I/O
  • Networking
    • Overview
    • CCDE Written
  • Tools
    • Overview
    • Pastebin
    • QR Code Generator
    • SVG Viewer
    • Function Grapher
    • Math Formula Generator
    • LaTeX Preview
    • Fancy Text Generator
    • Chess Coach
  • About
    • About Me

    • About This Website

    • Sponsor ♡

Chess Coach

Play chess against twenty characters from absolute beginner (200) all the way to raw Stockfish (3600+), each with their own personality, strengths, and weaknesses, 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. Runs entirely in your browser.
🏆 Join the online leaderboard: Optional. Saves your name, last 10 games (with PGN), and your blunder deck online. Skip it to stay fully local.
Enter your player code:
Playing online as code Keep the code somewhere safe. Enter it on another device to bring your record with you.
Choose your opponent
Your color
Time control
Coach
Bot pace
Board
Downloading Stockfish (~7 MB). It runs entirely 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.
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.
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
🔬 Analysis board
Pick a piece, then click squares to place it. Pick the ✕ to erase. Both kings are required.
Coach 0.0
Make your move. If you think for a while, I'll point you in the right direction.
Powered by Stockfish (GPLv3, via stockfish.js) and chess.js. 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.