Hobbes 3.0 is here!
The main changes in Hobbes 3.0 are NNUE improvements.
After eight weeks regenerating my dataset, I trained a couple of nets with the same arch which were decent improvements. Then I adopted the threat input architecture which has become the state-of-the-art in top a/b engines.
I should pay thanks to the many engine developers who developed this idea over the past few months. Lofty, Lily, Viren, JW, chef, the full Stockfish and Reckless teams, and many more. In particular the engines Reckless, Viridithas and Stormphrax were the implementations I referenced when writing my own. I haven't contributed anything original here; I'm just bringing Hobbes a bit closer to the SOTA developed by the names mentioned above.
The other notable change is the addition of Lazy SMP for multithreaded search (finally!)
Progression tests indicate a strength increase of 50 LTC Elo:
Elo | 49.96 +- 6.02 (95%)
Conf | 60.0+0.60s Threads=1 Hash=64MB
Games | N: 3004 W: 956 L: 527 D: 1521
Penta | [2, 173, 725, 598, 4]
https://openbench.nocturn9x.space/test/7571/
What's Changed
A curated selection of pull requests; for a comprehensive list, consult the changelog: 2.1...3.0
⚖️ Evaluation
- Threat inputs (#403)
- Increase TI L1 to 768 (#409)
- Add 10b 12ksn data to dataset (#399)
- Fine-tune only on most recent 12ksn data (#400)
🔍 Search
- First ever SMP tune (40k 20+0,2 4t) (#401)
- Cuckoo hashing for upcoming repetition detection (#390)
- Allow double and triple extensions in PV nodes (#402)
- Use fifty-move-rule buckets for zobrist hashing (#381)
⚡ Performance
- Switch to legal movegen (#376)
Acknowledgements
As always, I am extremely grateful to the community of engine developers for sharing their knowledge and expertise, especially in the AlphaBeta and Stockfish discords. Especially in this era of computer chess, in which low-effort, vibe-coded slop engines are infiltrating ratings lists and tournaments, it is a comfort to know there are still communities of human beings passionate about this hobby. Without those communities Hobbes would be a shadow of what it is today.