Chess-Nut-Engine/chess-sft-corpus-4x-eval

Chess SFT Eval and Benchmark Held-out evaluation splits and a frozen benchmark for Chess-Nut-Engine/chess-sft-corpus-4x. Every FEN in these files is excluded from generated training data (the blocklist is game-scoped: sibling positions of eval games are excluded too). Frozen from the 4x corpus generation run of 2026-07-06 (generator revision 3cd161b1078cdfa6598fba939f40250072adb524) Benchmark: 13,000 frozen examples across 9 splits; eval splits share the game-scoped blocklist… See the full description on the dataset page: https://huggingface.co/datasets/Chess-Nut-Engine/chess-sft-corpus-4x-eval.