Multi-Drafter Speculative Decoding with Alignment Feedback

Taehyeon Kim, Hojung Jung, Se-Young Yun


Abstract
Speculative decoding (SD) accelerates large language model (LLM) inference by using a smaller model to draft future tokens, which are then verified by the target LLM. This preserves generation quality by accepting only aligned tokens. However, individual drafters, often trained for specific tasks or domains, exhibit limited effectiveness across diverse applications. To address this, we introduce MetaSD, a unified framework that integrates multiple drafters into the SD process. MetaSD dynamically allocates computational resources to heterogeneous drafters by leveraging alignment feedback and framing drafter selection as a multi-armed bandit problem. Extensive experiments show MetaSD consistently outperforms single-drafter approaches.
Anthology ID:
2026.findings-acl.1629
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
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Pages:
32532–32573
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1629/
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Bibkey:
Cite (ACL):
Taehyeon Kim, Hojung Jung, and Se-Young Yun. 2026. Multi-Drafter Speculative Decoding with Alignment Feedback. In Findings of the Association for Computational Linguistics: ACL 2026, pages 32532–32573, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Multi-Drafter Speculative Decoding with Alignment Feedback (Kim et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1629.pdf
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