Mythos/Fable was the state of the art back in March, if not earlier.

So China is now only 4 months behind US frontier models now when the rule of thumb was 6 months just a little while ago.

To be fair the lag varies tremendously. When Deepseek first came out it was competitive with frontier lab models at the time.

It released in June..

To the public. Mythos has been in active use for quite a while.