GaiaChess NNUE networks
Neural networks (NNUE) for the GaiaChess UCI chess engine.
Files are append-only: a network file, once published, is never modified — engine releases pin an exact file name.
Architectures
Two incompatible generations live here. Each network carries a 16-byte integrity footer (architecture hash + content hash) and the engine refuses, loudly, a network whose architecture is not the one it was built for — so a file from one generation cannot be fed to an engine built for the other.
GaiaNet T1 (gaianet-t1-*, gaianet-t2-*, gaianet-t3*) — 12 king buckets × 768 PST
inputs + filtered threat features (~41K inputs) → 640 → CReLU + pairwise → 16 → 32 → 1,
8 output buckets.
GaiaNet T2b (gaianet-t2b-*) — the current generation. 12 king buckets × 768 PST inputs
(i16 rows) plus 64,368 auxiliary features in i8 rows: 4,560 pawn pairs and 59,808 filtered
piece-interaction (threat) features, accumulated into a 1024-wide layer → paired SCReLU →
16 → 32 → 1, with 8 material-based output buckets and a PSQT head. 87 MB per file.
Trained with Bullet (T1) and the in-house trainer (T2b).
Networks
| File | Architecture | Engine version | Notes |
|---|---|---|---|
gaianet-t1-1000.bin |
T1 | never shipped | archived for reproducibility: this network generated part of the training data used by its successors |
gaianet-t2-1000.bin |
T1 | 4.2.0 – 4.2.5 | previous default network |
gaianet-t3b-1000.bin |
T1 | unreleased | +12.0 ±9.5 Elo vs t2 (SPRT, 2588 games) |
gaianet-t3e-1100.bin |
T1 | unreleased | t3b fine-tuned for 100 more superbatches at lr/10 |
gaianet-t3e-1100b.bin |
T1 | unreleased | last T1 default: same weights as t3e-1100 plus the 16-byte integrity footer |
gaianet-t2b-e013.bin |
T2b | unreleased | previous default network. Fine-tune of the T2b line, 60 superbatches at lr 1e-4 cosine, WDL 0.4. +25.4 ±9.7 Elo vs its parent (SPRT) |
gaianet-t2b-e017.bin |
T2b | unreleased (default in main) |
current default network. Same recipe and same parent checkpoint as e013, 60 superbatches at lr 1e-4 cosine, with WDL 0.3 instead of 0.4. +3.2 ±2.6 Elo vs e013 (SPRT, 36 702 games) |
Usage
Networks are embedded into the engine at build time:
curl -L -o nets/gaianet-t2b-e017.bin \
"https://huggingface.co/jromanghf/gaiachess-networks/resolve/main/gaianet-t2b-e017.bin"
MODEL=nets/gaianet-t2b-e017.bin RUSTFLAGS="-C target-cpu=native" \
cargo build --release --features nnue
Or loaded at runtime through UCI: setoption name EvalFile value <path>.
License
GPL-3.0-or-later, same as the engine.