From the Academic Influence website:
Our measure of concentrated influence looks specifically at the ratio of combined influence scores for faculty and alumni to size of the undergraduate student body. So defined, concentrated influence is relevant to undergraduates, with higher concentrated influence indicating greater accessibility of undergraduates to influential faculty. Concentrated Influence™ | Academic Influence
50 Best Liberal Arts Colleges and Universities Ranked for Students | Academic Influence
Interestingly, Wesleyan falls to #3 when small tech colleges (cough, Caltech) are added to the mix:
50 Best Small Colleges and Universities Ranked for Students in 2023 | Academic Influence