Not an expert, but looks like they did a lot more work on the RL part (9 expert models, full sandbox access for agentic tasks, etc)?
most new effort in training comes in the late phase with RL techniques
the pretraining (slurping the internet) only goes so far, the new data being used is from human preferences and agent traces (designed and/or distilled)
most new effort in training comes in the late phase with RL techniques
the pretraining (slurping the internet) only goes so far, the new data being used is from human preferences and agent traces (designed and/or distilled)