What makes closers reliable is that they have a pitch that's so good that it doesn't matter if the secondaries aren't working or can't be thrown for strikes. Felix Bautista throws a fastball in the triple digits so even if the splitter isn't there he can get the job done more often than not. Nobody ever said "Zach Britton can't locate his slider, we're doomed." Webb looks awesome when all the stuff is working, just like Cano or Perez, the question is how often is that going to be the case.