fascinating stuff general masterclass.
the hard courts winning percentage for Lendl---at better than 82% (82.60 to be exact by the numbers provided by you)-- is phenomenal. he made 8 U.S. Open finals in a row.
its a shame for him and for his camp that it did not translate into a couple of 3 more U.S. Open titles.
all in all, he lost a total of 11 grand slam finals on all surfaces.
Vilas was a beast on clay. his total number of clay wins (634) are likely to stand forever. it is not that easy to win matches on clay with the sport becoming increasingly more demanding with each passing year. just at almagro as an example: all of his 12 titles are on clay. he was beaten soundly by dolgopolov the other day in Rio.
Connors might have the most exceptional winning percentage in many ways: he played and competed for 2 decades.
he was top 20 for 2 decades. that explains his 1531 total matches played and winning 1253 of them.
And still he managed to win better than 80% of his matches.