Blackbox Chess runs Stockfish across your last 10 to 100 games and names the exact mistakes that keep costing you, ranked by how much rating they actually cost. Not one game reviewed. Your whole history diagnosed, then a targeted plan to fix your worst leak.
Free for 10 games · No credit card · Results in about 60 seconds
What is Blackbox Chess? Blackbox Chess is a free web tool that analyzes your last 10 to 100 chess games using Stockfish, identifies the mistake types that repeat across your game history, and ranks them by how many rating points they cost you. Connect your Chess.com or Lichess account, or upload a PGN file, no sign-up required. The free analysis covers 10 games and names your #1 recurring mistake. The full report ($10) covers 100 games, ranks all patterns by severity, and includes a targeted fix course built around your specific weakness.
Import a PGN or connect your Lichess or Chess.com account. The more games, the clearer the pattern.
Every move, every game. Not a single game reviewed, your whole history scanned for what keeps going wrong.
See your recurring patterns ranked by how much they're actually costing you, so you know exactly what to fix.
“Pulling drills from your own real blunders instead of a random puzzle database is a genuinely good idea — the missing piece connecting know your leak to actually fix your leak.”
An independent Chess.com blogger ran 100+ of their own games through the full report. “They gave me the access for free, I’m writing about it because it was actually good, not because anyone’s paying me to say that.”
Read the full review on Chess.com → — carameezy
Analyze up to 10 games free. No account. No credit card. Takes about 60 seconds.