Ban&Pick: Enhancing Performance and Efficiency of MoE-LLMs via Smarter Routing

Yuanteng Chen, Peisong Wang, Yuantian Shao, Nanxin Zeng, Chang Xu, Jian Cheng


Abstract
Mixture-of-Experts (MoE) has become a key architecture for scaling large language models. Recent fine-grained MoE designs introduce hundreds of experts per layer, with multiple experts activated per token, enabling stronger specialization. However, during pre-training, routers are optimized mainly for stability and robustness: they converge prematurely and enforce balanced usage, limiting the full potential of model performance and efficiency at inference. In this work, we uncover two overlooked issues: (i) a few highly influential experts are underutilized due to premature and balanced routing decisions; and (ii) enforcing a fixed number of active experts per token introduces substantial redundancy. Instead of retraining or redesigning MoE architectures, we introduce Ban Pick, a training-free, plug-and-play strategy for smarter routing. Pick discovers and reinforces key experts, a small group with outsized impact on performance, leading to notable accuracy gains. Ban further dynamically prunes redundant experts based on layer and token sensitivity, delivering faster inference. Experiments on fine-grained MoE-LLMs (DeepSeek, Qwen3) across math, code, and general reasoning benchmarks demonstrate that Ban Pick delivers free performance gains and inference acceleration. For instance, on Qwen3-30B-A3B, it improves accuracy from 80.67 to 84.66 on AIME2024 and from 65.66 to 68.18 on GPQA-Diamond, while accelerating inference by 1.25× under the vLLM.
Anthology ID:
2026.findings-emnlp.678
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
14228–14253
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.678/
DOI:
Bibkey:
Cite (ACL):
Yuanteng Chen, Peisong Wang, Yuantian Shao, Nanxin Zeng, Chang Xu, and Jian Cheng. 2026. Ban&Pick: Enhancing Performance and Efficiency of MoE-LLMs via Smarter Routing. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 14228–14253, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Ban&Pick: Enhancing Performance and Efficiency of MoE-LLMs via Smarter Routing (Chen et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.678.pdf