🏆 Chessmont Open Dataset - 21.5M Elite Chess Games Now Available

We're excited to share the Chessmont Open Dataset, featuring 21.5+ million unique chess games with no duplicates or variants - the largest curated collection of elite chess games ever assembled.

📊 What's included in the Final Collection:

• 21.5M games from multiple premium sources (chessmont.pgn.zst)
• Lichess: All 2500+ ELO games in history (10+ moves, 180s+ time control) Chess.com: All 2500+ ELO games by Top 10K blitz players (10+ moves, 180s+)
• Complete archives: TWIC + PGN Mentor historical collections
• Unique game IDs in headers for easy referencing

🎯 Quality guarantees:

• No bullet games (minimum 3 minutes per game)
• No variant games
• No short games (minimum 10 moves/plies)
• Elite players only (2500+ ELO requirement) for chess.com and lichess sources
• Zero duplicates across all sources
• All games has been tested and is valid (Chess.js loadPgn for the test)

💾 Additional data:

• 1.35B unique FEN positions with occurrence statistics (fens-all.tsv.zst)
• 1.8B position index linking every position to its source game (chessmont-pgi.tsv.zst)

📄Other files :

🔗 Access: Available on Kaggle under Creative Commons license
💻 Code: Open source generator on GitHub

Perfect for engine training, opening research, and high-level chess analysis!
🍓Extract of the 4 first line of fens-all.tsv

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 

21512376

9683625

8431066

3397685

rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1

9933794

4453002

3932201

1548591

rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq - 0 1

7239529

3258936

2821942

1158651

For free games review see https://chessmont.com (no credentials required to link your chess.com / lichess account)