the relative importance of subject test scores on college admissions

Just HOW much of an influence do SAT II scores have on an applicant’s chances?
Are percentiles below 90 particularly harmful to an applicant’s competitive edge in the top 20 schools?

I myself have received mediocre scores. A 750 in Bio M and a 750 in History. I’d also expect a 750ish on Math.
While not bad, the national averages for these scores are in the mid-high 80s. Considering that I have a competitive standing in all other areas of my application, should I try for higher scores? Time and motivation are in short supply, and running fast.
Any feedback would be *helpful.

I suspect you’re overthinking some aspects and missing the point in other ways. 750 is fine. Period. But your shot at the schools noted on another thread will depend on your ability to pull together a solid whole application and supps. Unless you do that, you can’t state, up front, that you’re competitive in all respects. Decisions are made on more than stats, rigor, and ECs.

Percentiles are irrelvant to subject test scores. Score is all that matters and anything 700 or above shows mastery of the subject. Because it is usually high ranked colleges that would like to see subject test scores, it is usually your higher ranked high school students who take subject tests and thus you do not end up with the kind of percentile spread you will see with the SAT. There are math 2 SAT tests where an 800 is only the 80th percentile.If the colleges thought percentile was the key in that situation, no one would be admitted.