Courtesy of Professor Schwitzgebel.  The list says a lot about Anglophone philosophy (and SEP), perhaps a bit less about philosophy. 

(Yours truly is tied at #377 according to the Schwitzgebel method.  So close to greatness, but, alas, no cigar.   No cigar, either, for Alexander Nehamas, Jonathan Lear, John Gardner, Leslie Green, Seana Shiffrin, Imra Lakatos, Gilles Deleuze, Robert Pippin, Frederick Neuhouser, and Mark Wilson, among other surprising absences.)   

ADDENDUM:  A reader sends this Google N-Gram (based on searching all books in google) for the period 2000-2020, using philosophers from the top, middle, and bottom of the SEP list, plus some of the "no cigar" folks.  Of course, this would not distinguish between authored and edited works, and it would also pick up "impact" outside philosophy.