Just for the heck of it , I looked up some of the best known closers of the past and present. The elite ones seem to be in the high 80's in save percentage. Mariano Rivera , the indisputable GOAT , is at 89% , with a probably unbreakable record of 652 saves . Craig Kimbrel appears to be the only one, past or present, with a 90% save percentage. And it is very doubtful that he will be able to maintain that rate as he pitches into the twilight of his career . So , 90% is indeed the gold standard , and then some.