Your footnote 3 seems to imply that the low number for o1 and Grok3 is without parallelism, but I don't think it's publicly known whether they use internal parallelism? So perhaps the low number already uses parallelism, while the high number uses even more parallelism?

Also, curious if you have any intuition as to why the no-parallelism number for AIME with Claude (61.3%) is quite low (e.g., relative to R1 87.3% -- assuming it is an apples to apples comparison)?