Native MarinSkyRL Tinker-style OPD: one step from SFT step 400
This PEFT LoRA adapter is the result of one full-shape, chosen-token sampled reverse-KL optimizer update in MarinSkyRL. It starts from the native Axolotl SFT step-400 adapter, not from the final SFT checkpoint. Load it on the pinned base model Qwen/Qwen3.5-9B-Base revision 68c46c4b3498877f3ef123c856ecfde50c39f404.
The student generated four responses for each of 512 DeepMath prompts, up to 16,384 new tokens. The chosen-token teacher was Qwen/Qwen3.5-9B revision c202236235762e1c871ad0ccb60c8ee5ba337b9a. The teacher and student used the same tokenizer. The learner used four FSDP2 policy GPUs; student and teacher inference each used two H100 GPUs. The learning rate was 1e-4 and the LoRA rank was 128.
An independent 30-question AIME 2024 evaluation scored 26/30 correct; two answers reached the length cap, so this is not a fully comparable benchmark result. The SFT step-400 starting point scored 19/30 under the same local protocol. The reproduction bundle holds retained evaluation outputs; launch manifests and exact source/config snapshots are in the experiment artifact bundle.
This is a target-score demonstration, not a 200-step trajectory reproduction of the Thinking Machines recipe. The published recipe begins OPD after 3,000 SFT steps. Historical per-token teacher score tensors and student training rollouts were not retained for this gate.
SHA-256: adapter_model.safetensors = c706c786c331bfbab4bb077bb69149b2092e5e7f28544ef531e63d6cb38da071; adapter_config.json = 994763a467f94f8628adf720c4652bd580dd3a2a8bd7c41c70fc80bec70cfd8e.
We release our tools to the public with the intent that they are used safely, ethically, and responsibly. They are meant to contribute to the public's understanding of science, and aid in its advancement. By using this Marin model, you agree to comply with all applicable law.