Every tool you need to go from blunder-prone to tournament-ready — blunder detection, real-time threat overlay, Stockfish position analysis, AI coaching, opening repertoire building, and tactical drilling with spaced repetition.
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Every move in your game is classified — brilliant, excellent, good, inaccuracy, mistake, or blunder — using Stockfish engine evaluation. After each game you get a centipawn-loss breakdown, an accuracy score, and the engine's best continuation at every critical moment. Stop repeating the same tactical oversights by seeing exactly where your calculation breaks down.
Navigate any position and instantly see every attack, hanging piece, and king-safety issue rendered directly on the board. The threat overlay highlights enemy attacks in red and your defensive resources in green — giving you the whole-board awareness that separates 1800-rated players from 1200-rated ones. Critical for tournament preparation and post-game review.
Ask the engine to evaluate any position at depth 18+. D4 Chess Club™ runs Stockfish in the browser via WebAssembly so analysis is instant and private. You get the principal variation, evaluation bar, and top three candidate moves — everything you'd see in a desktop GUI, inside a clean training interface built for club players.
Hundreds of tactical puzzles organized by theme — forks, pins, skewers, discovered attacks, back-rank mates. The spaced-repetition scheduler (SM-2) tracks which patterns you miss and resurfaces them at exactly the right interval so knowledge sticks. Free accounts get 5 puzzles per day; Premium is unlimited.
Choose any Elo from 1000 to 3200 and play a rated game against the engine. The difficulty scales smoothly so you can find the exact level that challenges without crushing you — critical for deliberate practice and building calculation confidence before rated tournaments.
Ranked by accuracy, XP, puzzle rating, and improvement trend across the D4 Chess Club™ community. See how you stack up week over week and identify whether your rating progress matches your training investment. Club tournament brackets are on the roadmap.
Upgrade to unlock the AI Socratic coach, personalized opponent analysis, the opening repertoire builder, and all structured courses.
Instead of just showing you the best move, the AI coach asks you targeted questions about your mistakes — 'What piece was left undefended after that knight move?' — forcing active recall and building pattern recognition that lasts. This Socratic method is how strong coaches actually teach chess at the club level.
Ask the AI to walk through any specific position from your game and explain the threats, weak squares, pawn structure implications, and the right strategic plan. The coach ties every explanation to the moves you actually played — not generic theory. Perfect for preparing for specific opponents or understanding your own tendencies.
Browse 3,700+ named openings with theory, ideas, and typical plans. The repertoire builder lets you drill your personal lines forwards and backwards from memory, flagging where you deviate from your prep. Includes the Opening Principles course — 10 core principles illustrated with 30 grandmaster games.
23 structured lessons on forks, pins, skewers, and discovered attacks taught from real grandmaster games. Each lesson introduces the pattern, shows 3–5 master examples, then tests you with unseen positions. Completing the course typically adds 100–200 Elo of tactical sharpness for club-level players.
Every blunder is a pattern. D4 Chess Club™ trains you to see them coming — with blunder detection, threat overlays, and AI coaching that actually explains the why.
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