Ishaank/fruitflychess-connectome

Fruit Fly Chess Connectome

A chess policy/value network constrained by the wiring topology of the complete Drosophila larval connectome (Winding et al., Science, 2023).

Repository channels

• —dev/checkpoints/ contains immutable training gates uploaded automatically.
• —prod/model.pt is the manually promoted PyTorch checkpoint. Automation never overwrites production.
• —browser/ contains the inference-only ONNX release used by fruitflychess.com.
• —benchmarks/ contains reproducible Stockfish-anchored evaluation reports.

The initial production promotion is the best validation checkpoint available at publication time: step 1,170,000, validation loss 2.6849. The currently deployed browser release is separately frozen at step 600,000.

Architecture

• —2,952 neurons and 110,677 fixed connectome edges
• —2,820,249 learned parameters
• —256 sensory neurons and 256 motor neurons
• —8 recurrent steps
• —4,672 move-policy outputs and 3 win/draw/loss outputs
• —greedy legal-move selection; no search

Measured strength

Ratings combine games against Stockfish 18 limited to 1320, 1600, 1800, and 2000 Elo. Each checkpoint plays 40 games per anchor with colors balanced, 50 ms move time, a 4,000-node cap, and no neural search. These ratings are protocol-specific estimates, not FIDE or Chess.com ratings.

Browser files

The ONNX release excludes optimizer state and unsafe pickle data. Its manifest records SHA-256 hashes for both the model and visualization metadata; the browser verifies those hashes before inference.