Add dataset card

README.md

@@ -1,3 +1,26 @@
+---
+license: cc0-1.0
+task_categories:
+- other
+language:
+- en
+tags:
+- chess
+- stockfish
+- distillation
+- policy
+- value
+size_categories:
+- 100K<n<1M
+configs:
+- config_name: default
+  data_files:
+  - split: train
+    path: data/train-*.parquet
+  - split: validation
+    path: val/val-*.parquet
+---
+
 # xLeverd/chess — Stockfish distillation dataset
 
 Synthetic chess positions for supervised policy/value distillation.
@@ -29,12 +52,21 @@ Synthetic chess positions for supervised policy/value distillation.
 
 ```bash
 python distill.py --target 100000 --workers 8 --depth 12 --out data
+python distill.py --target 5000 --workers 6 --depth 12 --seed 987654 --out val
 python upload_hf.py
 ```
 
 Teacher: Stockfish 19, `Skill Level 20`, `Hash 16`, `Threads 1`, depth 12.
 Position generator: Stockfish `Skill Level 3..7`, depth 1–3, 6–36 plies.
 
+## Current version (v1)
+
+- 100,000 train rows, 5,000 validation rows.
+- 99,554 unique train FENs; 0 illegal moves / 0 SAN mismatches in validation.
+- Generated at ~156 positions/s on 8 CPU workers.
+- Median position length: 14 plies; WDL split: 65% draw, 21% win, 14% loss
+  from side-to-move POV.
+
 ## Intended use
 
 Policy/value distillation for a small chess model, then optional MCTS.