What it is
Trained on 1,000,000 positions sampled from random play and labeled with
Stockfish's best move (single-move samples of the form 1.<san>). The arena
queries a model with a constant "1." prompt and constrains the output to the
legal moves of the current position (via outlines), so this model learns a
distribution over strong move shapes rather than board-specific tactics.
Strengths / limitations
- ✅ Always outputs a legal move — it never forfeits on an illegal move,
which is a common failure mode for LLM chess entries.
- ✅ Loads as a standard
transformers causal LM; drop-in for the arena.
- ⚠️ Plays position-blind. By design the arena never shows the model the
board (the prompt is always
"1."), so no model in that arena — including
this one — can calculate tactics. Expect casual, not strong, play.
Usage
from transformers import AutoModelForCausalLM, AutoTokenizer
tok = AutoTokenizer.from_pretrained("TobiasLogic/gambit-gpt")
model = AutoModelForCausalLM.from_pretrained("TobiasLogic/gambit-gpt")
Or enter TobiasLogic/gambit-gpt directly in the arena Space.
Roadmap
v2 will train on master-game openings for a stronger move prior. A board-aware
variant (that actually sees the position) is planned for real UCI play.