### R2 Training Checkpoints (Stages 1–3)

We release the checkpoints from the three-stage training pipeline described in the third version of our paper. Stage 1 uses supervised fine-tuning; Stage 2 produces two checkpoints through soft-label distillation; and Stage 3 combines them through model soup to produce the final R2 models.

| Stage   | Checkpoint               | Nano                                                                                                              | Small                                                                                                               | Large                                                                                                               |
| :------ | :----------------------- | :---------------------------------------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------ | :------------------------------------------------------------------------------------------------------------------ |
| Stage 1 | Supervised fine-tuning   | [KaLM-Reranker-V1-Nano-R2-Stage1](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Nano-R2-Stage1)                 | [KaLM-Reranker-V1-Small-R2-Stage1](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Small-R2-Stage1)                 | [KaLM-Reranker-V1-Large-R2-Stage1](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Large-R2-Stage1)                 |
| Stage 2 | Distillation (`r64-a32`) | [KaLM-Reranker-V1-Nano-R2-Stage2-r64-a32](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Nano-R2-Stage2-r64-a32) | [KaLM-Reranker-V1-Small-R2-Stage2-r64-a32](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Small-R2-Stage2-r64-a32) | [KaLM-Reranker-V1-Large-R2-Stage2-r64-a32](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Large-R2-Stage2-r64-a32) |
| Stage 2 | Distillation (`r96-a48`) | [KaLM-Reranker-V1-Nano-R2-Stage2-r96-a48](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Nano-R2-Stage2-r96-a48) | [KaLM-Reranker-V1-Small-R2-Stage2-r96-a48](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Small-R2-Stage2-r96-a48) | [KaLM-Reranker-V1-Large-R2-Stage2-r96-a48](https://huggingface.co/Yuki131/KaLM-Reranker-V1-Large-R2-Stage2-r96-a48) |
| Stage 3 | Final R2 model           | [KaLM-Reranker-V1-Nano-R2](https://huggingface.co/KaLM-Embedding/KaLM-Reranker-V1-Nano-R2)                        | [KaLM-Reranker-V1-Small-R2](https://huggingface.co/KaLM-Embedding/KaLM-Reranker-V1-Small-R2)                        | [KaLM-Reranker-V1-Large-R2](https://huggingface.co/KaLM-Embedding/KaLM-Reranker-V1-Large-R2)                        |