Total runs:
357.6K
Run Growth:
-69.4K
Growth Rate:
-19.40%
Sponsored by
APIMart
mlabonne / LFM2.5-230M-Chess
Model's Last Updated: Septiembre 16 2026
text-generation
Introduction of LFM2.5-230M-Chess
Model Details of LFM2.5-230M-Chess
LFM2.5-230M-Chess
A 230M chess engine with a language model interface, fine-tuned from LFM2.5-230M-Base using Stockfish distillation.
Every possible chess move is a single token in the vocabulary. The model reads a position as a fixed 80-token prompt, predicts its own win probability, then predicts one move token. The host masks the move logits to the legal moves, so the model can never play an illegal move.
It plays at roughly 2004 Elo with a shallow depth-3 search on top, and roughly 1500 with the raw one-pass policy.
Demo: Play it in your browser with the ChessLFM Space .
Usage
import json
from transformers import AutoModelForCausalLM
model = AutoModelForCausalLM.from_pretrained("mlabonne/LFM2.5-230M-Chess")
token_ids = json.load(open("token_ids.json"))
Each move takes two short forward passes:
- Build the 80-token prompt from the FEN. It encodes the 64 squares, side to move, castling rights, en passant file, halfmove clock, repetition count, and the last 8 plies.
-
Argmax over the 64 value tokens gives the model evaluation, where
<v:k>means a win probability in[k/64, (k+1)/64). -
Append that value token and
<|bestmove|>, mask the move logits to the legal moves, and take the argmax.
You can find the 2,106 added token IDs in
token_ids.json
(it starts at 64402).
Runs of mlabonne LFM2.5-230M-Chess on huggingface.co
1.7K
Total runs
0
24-hour runs
51
3-day runs
113
7-day runs
1.5K
30-day runs
More Information About LFM2.5-230M-Chess huggingface.co Model
Url of LFM2.5-230M-Chess
LFM2.5-230M-Chess huggingface.co Url
Provider of LFM2.5-230M-Chess huggingface.co
Other API from mlabonne
Updated:Mayo 19 2025
Total runs:
33.0K
Run Growth:
3.7K
Growth Rate:
11.21%
Total runs:
29.9K
Run Growth:
1.3K
Growth Rate:
4.18%
Total runs:
15.2K
Run Growth:
419
Growth Rate:
2.76%
Total runs:
9.1K
Run Growth:
225
Growth Rate:
2.46%
Total runs:
8.8K
Run Growth:
77
Growth Rate:
0.88%
Total runs:
8.2K
Run Growth:
552
Growth Rate:
6.74%
Total runs:
8.2K
Run Growth:
429
Growth Rate:
5.26%
Total runs:
6.7K
Run Growth:
0
Growth Rate:
0.00%
Total runs:
6.6K
Run Growth:
-2.4K
Growth Rate:
-35.08%
Total runs:
5.8K
Run Growth:
1.1K
Growth Rate:
19.66%
Total runs:
3.9K
Run Growth:
232
Growth Rate:
7.88%
Total runs:
3.7K
Run Growth:
-24
Growth Rate:
-0.67%
Total runs:
3.0K
Run Growth:
-99
Growth Rate:
-3.35%
Total runs:
2.1K
Run Growth:
519
Growth Rate:
24.73%
Total runs:
2.1K
Run Growth:
0
Growth Rate:
0.00%
Total runs:
1.6K
Run Growth:
592
Growth Rate:
37.12%
Total runs:
1.5K
Run Growth:
76
Growth Rate:
5.05%
Total runs:
1.5K
Run Growth:
-97
Growth Rate:
-6.58%
Total runs:
1.4K
Run Growth:
104
Growth Rate:
7.52%
Total runs:
1.4K
Run Growth:
1.3K
Growth Rate:
97.91%
Total runs:
1.1K
Run Growth:
110
Growth Rate:
10.12%
Total runs:
976
Run Growth:
435
Growth Rate:
44.57%
Total runs:
669
Run Growth:
0
Growth Rate:
0.00%
Total runs:
621
Run Growth:
290
Growth Rate:
46.70%
Total runs:
483
Run Growth:
320
Growth Rate:
66.25%
Total runs:
421
Run Growth:
-19
Growth Rate:
-4.51%
Total runs:
407
Run Growth:
-148
Growth Rate:
-37.37%
Total runs:
402
Run Growth:
-1.6K
Growth Rate:
-409.45%
Total runs:
379
Run Growth:
-118
Growth Rate:
-31.13%
Total runs:
372
Run Growth:
-16
Growth Rate:
-4.30%
Total runs:
358
Run Growth:
0
Growth Rate:
0.00%
Total runs:
354
Run Growth:
12
Growth Rate:
3.39%
Total runs:
348
Run Growth:
21
Growth Rate:
6.03%
Total runs:
333
Run Growth:
13
Growth Rate:
3.90%
Total runs:
324
Run Growth:
-7
Growth Rate:
-2.16%
Total runs:
322
Run Growth:
35
Growth Rate:
10.87%
Total runs:
311
Run Growth:
-198
Growth Rate:
-63.67%
Total runs:
308
Run Growth:
0
Growth Rate:
0.00%
Total runs:
271
Run Growth:
187
Growth Rate:
69.00%
Total runs:
205
Run Growth:
73
Growth Rate:
35.44%
Total runs:
176
Run Growth:
0
Growth Rate:
0.00%
Total runs:
175
Run Growth:
-119
Growth Rate:
-68.00%
Total runs:
167
Run Growth:
-64
Growth Rate:
-37.87%
Total runs:
159
Run Growth:
84
Growth Rate:
52.83%
Total runs:
158
Run Growth:
64
Growth Rate:
40.51%
Total runs:
157
Run Growth:
-829
Growth Rate:
-528.03%
Total runs:
157
Run Growth:
17
Growth Rate:
10.83%
Total runs:
148
Run Growth:
16
Growth Rate:
10.81%
Total runs:
131
Run Growth:
-354
Growth Rate:
-270.23%
Total runs:
128
Run Growth:
43
Growth Rate:
33.59%
Total runs:
116
Run Growth:
63
Growth Rate:
54.31%
Total runs:
111
Run Growth:
-49
Growth Rate:
-44.14%
Total runs:
103
Run Growth:
19
Growth Rate:
18.45%
Total runs:
98
Run Growth:
-316
Growth Rate:
-322.45%
Total runs:
92
Run Growth:
-134
Growth Rate:
-127.62%
Total runs:
89
Run Growth:
-178
Growth Rate:
-200.00%
Total runs:
85
Run Growth:
-444
Growth Rate:
-522.35%
Total runs:
74
Run Growth:
-32
Growth Rate:
-45.07%
Total runs:
72
Run Growth:
51
Growth Rate:
70.83%
Total runs:
70
Run Growth:
-29
Growth Rate:
-38.67%
Total runs:
69
Run Growth:
-23
Growth Rate:
-33.33%
Total runs:
58
Run Growth:
-40
Growth Rate:
-68.97%
Total runs:
56
Run Growth:
-19
Growth Rate:
-30.65%
Total runs:
53
Run Growth:
-16
Growth Rate:
-30.19%
Total runs:
50
Run Growth:
-59
Growth Rate:
-115.69%
Total runs:
49
Run Growth:
0
Growth Rate:
0.00%
Total runs:
47
Run Growth:
0
Growth Rate:
0.00%
Total runs:
45
Run Growth:
0
Growth Rate:
0.00%
Total runs:
43
Run Growth:
36
Growth Rate:
65.45%
Total runs:
43
Run Growth:
6
Growth Rate:
13.95%