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Lightning OPD: Efficient Post-Training for Large Reasoning Models with Offline On-Policy Distillation

13 Pith papers cite this work. Polarity classification is still indexing.

13 Pith papers citing it
abstract

On-policy distillation (OPD) is an effective post-training paradigm for large language models but requires a live teacher server throughout training, resulting in substantial infrastructure overhead. We investigate whether OPD can be performed offline by precomputing teacher log-probabilities once over SFT rollouts and reusing them during training. We find that naively doing so fails to reliably match standard OPD, and trace the root cause to a previously overlooked condition we term teacher consistency, requiring that the same teacher be used for both supervised fine-tuning and OPD. Violating this condition introduces a gradient bias that degrades performance for both offline and online OPD. Building on this insight, we propose Lightning OPD, an offline on-policy distillation framework that enforces teacher consistency and eliminates the need for a live teacher server entirely. We prove that, under teacher consistency, Lightning OPD shares the same optimum as standard OPD, with bounded gradient discrepancy and an implicit regularization effect that helps prevent policy drift. Experiments on math reasoning and code generation show that Lightning OPD achieves comparable performance to standard OPD while delivering 4.0x higher training efficiency. Starting from an SFT-initialized Qwen3-8B-Base model, Lightning OPD reaches 69.9% on AIME 2024 in just 30 GPU hours. Lightning OPD further scales to MoE architectures, training Qwen3-30B-A3B to 71.0% on AIME 2024 on a single 8xH100 node, substantially lowering the barrier for academic research on LLM post-training. Our code is released at https://github.com/jet-ai-projects/Lightning-OPD.

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2026 13

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representative citing papers

Zone of Proximal Policy Optimization: Teacher in Prompts, Not Gradients

cs.CL · 2026-06-16 · unverdicted · novelty 7.0

ZPPO improves distillation to small vision-language models by using binary and negative candidate prompts plus a replay buffer for hard questions, outperforming standard distillation and GRPO on a 31-benchmark suite with largest gains at the 0.8B scale.

DISA: Offline Importance Sampling for Distribution-Matching LLM-RL

cs.LG · 2026-05-17 · unverdicted · novelty 7.0

DISA decouples partition function estimation using offline importance sampling for distribution-matching LLM-RL, matching or exceeding online baselines like FlowRL on math and code benchmarks while retaining more strategy diversity.

Rubric-based On-policy Distillation

cs.LG · 2026-05-08 · unverdicted · novelty 7.0

Rubric-based on-policy distillation allows training student models using only teacher responses by generating scoring rubrics from contrasts and using them for on-policy optimization, achieving superior performance and up to 10x better sample efficiency than logit-based approaches.

DOPD: Dual On-policy Distillation

cs.AI · 2026-06-29 · unverdicted · novelty 5.0

DOPD is an advantage-aware dual distillation method that dynamically assigns token supervision from either privileged teacher or student to transfer capability while mitigating non-replicable information asymmetry in on-policy distillation.

citing papers explorer

Showing 13 of 13 citing papers.

  • Zone of Proximal Policy Optimization: Teacher in Prompts, Not Gradients cs.CL · 2026-06-16 · unverdicted · none · ref 31 · internal anchor

    ZPPO improves distillation to small vision-language models by using binary and negative candidate prompts plus a replay buffer for hard questions, outperforming standard distillation and GRPO on a 31-benchmark suite with largest gains at the 0.8B scale.

  • DISA: Offline Importance Sampling for Distribution-Matching LLM-RL cs.LG · 2026-05-17 · unverdicted · none · ref 51 · internal anchor

    DISA decouples partition function estimation using offline importance sampling for distribution-matching LLM-RL, matching or exceeding online baselines like FlowRL on math and code benchmarks while retaining more strategy diversity.

  • Rubric-based On-policy Distillation cs.LG · 2026-05-08 · unverdicted · none · ref 27 · internal anchor

    Rubric-based on-policy distillation allows training student models using only teacher responses by generating scoring rubrics from contrasts and using them for on-policy optimization, achieving superior performance and up to 10x better sample efficiency than logit-based approaches.

  • Regime-Aware Peer Specialization for Robust RAG under Heterogeneous Knowledge Conflicts cs.CL · 2026-06-29 · unverdicted · none · ref 34 · internal anchor

    RAPS-DA improves RAG robustness to heterogeneous knowledge conflicts by training regime-specific peer specialists with hard routing and a dual-layer token selector for focused supervision.

  • SEAD: Competence-Aware On-Policy Distillation via Entropy-Guided Supervision cs.CL · 2026-06-26 · unverdicted · none · ref 10 · internal anchor

    SEAD applies entropy-guided token selection, KL annealing, and easy-to-hard curriculum to on-policy distillation and reports +4.8 average accuracy gain over vanilla OPD on six math benchmarks with OLMo-3 models.

  • RLCSD: Reinforcement Learning with Contrastive On-Policy Self-Distillation cs.LG · 2026-06-10 · unverdicted · none · ref 25 · internal anchor

    RLCSD contrasts teacher-student distributional gaps under correct versus wrong hints to suppress privilege-induced style drift and concentrate supervision on task tokens, outperforming GRPO and prior OPSD on Qwen3 and Olmo models.

  • Prefix Teach, Suffix Fade: Local Teachability Collapse in Strong-to-Weak On-Policy Distillation cs.CL · 2026-05-13 · unverdicted · none · ref 33 · 2 links · internal anchor

    Local teachability collapse occurs in later trajectory segments during strong-to-weak OPD; a margin-based release rule using top-K teacher advantage and BIC change-point detection on sentence segments outperforms full-trajectory supervision on five in-domain benchmarks and preserves out-of-domain pe

  • SimCT: Recovering Lost Supervision for Cross-Tokenizer On-Policy Distillation cs.CL · 2026-05-08 · unverdicted · none · ref 18 · 2 links · internal anchor

    SimCT enlarges the supervision space in cross-tokenizer on-policy distillation using short jointly tokenizable multi-token continuations, producing consistent gains over shared-token baselines on math and code benchmarks.

  • Uni-OPD: Unifying On-Policy Distillation with a Dual-Perspective Recipe cs.LG · 2026-05-05 · conditional · none · ref 40 · internal anchor

    Uni-OPD improves on-policy distillation via student-side data balancing for informative rollouts and teacher-side outcome-guided margin calibration that restores order consistency with rewards.

  • DOPD: Dual On-policy Distillation cs.AI · 2026-06-29 · unverdicted · none · ref 40 · internal anchor

    DOPD is an advantage-aware dual distillation method that dynamically assigns token supervision from either privileged teacher or student to transfer capability while mitigating non-replicable information asymmetry in on-policy distillation.

  • Filter, Then Reweight: Rethinking Optimization Granularity in On-Policy Distillation cs.LG · 2026-06-01 · unverdicted · none · ref 30 · internal anchor

    FiRe-OPD introduces a two-stage filter-then-soft-reweight procedure for trajectory- and token-level supervision in on-policy distillation, claiming gains over prior token-level methods.

  • SOD: Step-wise On-policy Distillation for Small Language Model Agents cs.CL · 2026-05-08 · conditional · none · ref 27 · internal anchor

    A step-wise reweighting of on-policy distillation, based on per-step student-teacher divergence, improves tool-integrated reasoning in 0.6B and 1.7B language models.

  • A Formula-Driven Survey and Research Agenda for On-Policy Distillation cs.AI · 2026-06-22 · unverdicted · none · ref 46 · internal anchor

    A survey creates a taxonomy for on-policy distillation in LLMs that separates temporal credit assignment from vocabulary-level probability routing.