
Tiger-1a chess engine release
Hi there!
I have been working on this engine for the past 6 months now and I think it's now ripe to be thrown into the wild.
The engine features a NNUE trained using nnue-pytorch. It is comparatively very small.
To accommodate this I tried to make the engine's search as buffed as possible.
Anyway here's the specific details of the engine for the nerds:
Evaluation
- NNUE Architecture: HalfKAv2_hm^
- Network Layers: L1=128, L2=32, L3=8 with PSQT buckets
- Network File: Acherontia (88mm.nnue)
- Incremental NNUE Evaluation: Efficient position updates with feature transformer
- Tapered Material Evaluation: Smooth transition between middlegame and endgame
- Customizable NNUE Scaling: Adjust evaluation strength via UCI option
Search
- Core Algorithm: Alpha-Beta Negamax with fail-soft
- Move Ordering: Principal Variation Search (PVS)
- Depth: Iterative Deepening up to 64 plies
- Transposition Table: Configurable 1-4096 MB with generation-based aging
- Pruning Techniques:
- Late Move Reductions (LMR) with logarithmic formula
- Null Move Pruning
- Reverse Futility Pruning
- Futility Pruning
- ProbCut
- Delta Pruning in quiescence search
- Move Ordering Heuristics:
- Killer Move Heuristic
- History Heuristic
- Continuation History (4 ply)
- Countermove Heuristic
- Extensions:
- Singular Extensions
- Static exchange evaluation (SEE) for capture ordering and pruning
- Time Management: Aspiration Windows with soft and hard time limits
- Quiescence Search: Delta pruning and tactical awareness
- Parallel Search: Multi-threaded support (up to 8 threads)
And here's the Github release page for the testers and alike: https://github.com/Azrael337/Tiger-1-Chess-Engine/releases/tag/chess-engine