Round 3 (spring/late-spring) admissions?

I don't have stats and don't remember seeing any that break down acceptance rates by round. But I have talked to a number of adcom directors and also posed the question on chats, and there is not question that it is harder to get accepted third round than first and second round. The slight exception is MIT, which has only two rounds. For MIT the second round has a lower acceptance rate. A few years ago, the quoted rate was 18% acceptance rate first round and 7% acceptance rate second round.

Third round admitted applicants tend to add to a school's diversity or, if from a common applicant background, have an uncommonly high level of achievement. If you can apply by January, do it.

If you can't apply by January, it may still make more sense for you to apply third round than wait until fall, but we are too early to make that calculation. For not, turn your attention to that stack of applications and work on them.

Good luck!