According to Brown’s common data set, 25% of matriculating students reported class rank, and 75% of students did not report rank. The rank figures listed on Stanford and Brown’s websites are only for the small minority of students who reported rank, which is almost certainly biased towards applicants with higher rank. So the actual rank percentages for the full class is almost certainly lower than suggested by such reports. Acceptance rates by rank is reported on Brown’s website are below.
Applicants Who Reported Class Rank – 9.9% acceptance rate
Applicants Who Did Not Report Class Rank – 9.8% acceptance rate
Among the 25% who reported rank…
Val – 19% acceptance rate
Sal – 14% acceptance rate
Other Top 10% – 10% acceptance rate
Not in Top 10% – 2% acceptance rate
Among the minority who submitted rank ,there does appear to be a notable difference in acceptance rate between those in top 10% rank and not in top 10% rank. However, this does not mean that rank was the direct cause of the rejection. Brown holistically looks at the full transcript, considering grades and rigor, which are highly correlated with rank; rather than just plugging into a formula based on rank. Students with lower ranks tend to also have worse grades, worse rigor, worse LORs, etc. If a student with a lower rank is rejected, is that because of his HS’s reported rank? Or is that because he had unimpressive grades, rigor, LORs, essays, etc.? This makes it very difficult to draw conclusions about the chances of an applicant who has lower class rank due to attending a competitive HS or a HS’s goofy weighting system; but excels in the other aspects of the holistic application, including grades and rigor.
Back when I applied to colleges, I fit this description. I had an unimpressive class rank at a typical public HS – probably barely top 10% HS rank, if that. However, I also took a large number of courses at a nearby university that were not counted towards my HS rank, and received A’s in all of these courses, some of which were probably at a higher level of rigor than had been taken by anyone in the history of my HS. If you also considered the external courses and level of rigor in rank, then my modified rank would have been much more impressive. Stanford, Brown, MIT, and others all were able to figure out the combination of transcripts and accepted me; while rejecting several others from my HS with higher HS class ranks. While higher rank is obviously better, I wouldn’t assume that you are doomed, if you kill your rank by taking unweighted electives you enjoy instead of going for val/sal by taking the maximum possible number of maximum weighted classes.