I agree that Ivy League schools possess top academic students and as a group should significantly outperform most competitor schools in terms of elite graduate school admissions. My point (although there is insufficient accessible data to prove it) is that they outperform their peers in excess to what I would expect it to be.
In your attachment, Top 240 Feeder Schools for ABA applicants 2015-2017, the Ivy schools have significantly higher mean LSAT scores (ballpark difference is an increase of 5-10 points). But a large number of Top 240 feeder schools have maximum scores (173-180, 98-99.9th percentiles) that significantly exceed those means. Assuming a normal distribution of LSAT scores, there should be a significant # of LSAT takers from non-Ivy league schools whose scores significantly exceed the Ivy League mean of ~ 165, especially considering the fact that the non-Ivy League law school applicant population greatly dwarfs the Ivy League. There aren’t many non-Ivy League matriculants on the T14 law school class lists (that are accessible to me). Most schools have zero representation and those that do typically only have 1 representative.
Here’s an example using a 3 year average from your attachment.
Florida State University
applicants/year 574
MCAT mean 157.43
MCAT max 179.33
Yale
applicants/year 190
MCAT mean 167.99
MCAT max 180
According to the Yale Daily News, 25% of the Yale Law students in 2011 attended Harvard or Yale and 50% attended an Ivy League school or Stanford. I think those are disproportionately high numbers if the selection process is solely based on GPA and LSAT score.
This topic has also been brought up previously.
Based on the above list, Yale had 162 alumni attending Yale/Stanford/U Chicago. Yale had the most representatives for both Stanford and Yale. It was ranked #4 for U Chicago. FSU only had 5 alumni attending those 3 schools- even though FSU probably had 3 times as many law school applicants as Yale.
**Yale and Stanford Law Schools are no longer publicizing the actual # of matriculants with their college of origin.