Rohan Paul (@rohanpaul_ai)T2·72 pts
- BPB is not truly tokenizer-agnostic: even untrained models yield different BPB scores under different tokenizers
- Across models sharing a recipe but differing in tokenizer, BPB correlated with task scores only from +0.02 to −0.30
- When comparing tokenizers, check task accuracy on the same text rather than treating lower BPB as proof of a better model