Confidence Leaps in LLM Reasoning: Early Stopping and Cross-Model Transfer

Pavel Tikhonov, Ivan Oseledets, Elena Tutubalina


Abstract
We challenge the common assumption that Large Language Models (LLMs) build confidence gradually during reasoning. Instead, we find that conviction is often reached in a discrete "moment of insight", characterized by a sudden and sharp increase in an answer’s probability-a phenomenon we term a "confidence leap". Leveraging this discovery, we introduce a training-free, model-agnostic early-stopping heuristic that halts generation upon detecting such a leap, significantly reducing the generation length without sacrificing accuracy. We also demonstrate that the reasoning text leading up to this leap is semantically potent and transferable: feeding this partial reasoning to a different model family substantially boosts its performance. This suggests that the "confidence leap" marks a shared, interpretable reasoning milestone, not just a model-specific statistical artifact.
Anthology ID:
2026.eacl-short.43
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
602–616
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-short.43/
DOI:
Bibkey:
Cite (ACL):
Pavel Tikhonov, Ivan Oseledets, and Elena Tutubalina. 2026. Confidence Leaps in LLM Reasoning: Early Stopping and Cross-Model Transfer. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 2: Short Papers), pages 602–616, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Confidence Leaps in LLM Reasoning: Early Stopping and Cross-Model Transfer (Tikhonov et al., EACL 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-short.43.pdf
Checklist:
 2026.eacl-short.43.checklist.pdf