Why Do AI Labs Keep Their Best Models Internal?

Dylan Patel says frontier labs are keeping months of new-model progress inside the company, because once a model is public other people can distill it. Anthropic had Mythos ready in February. What the public got, many months later, is a limited version called Fable. The full Mythos model is still not out. Safety cards noted two other models after Mythos.

OpenAI has held finished models back the same way. One was done a couple of months before release. Another was shown solving math problems in a blog post and still was not released. The public gap versus Chinese open-source models is still about six months, and the labs have kept further months internal. Anthropic is likely to release a new model in the coming weeks around its IPO, and OpenAI is likely to release one too, while both keep a lot of the work internal.