Custom table I just pulled together: http://www.fangraphs.com/leaders.aspx?pos=all&stats=sta&lg=all&qual=y&type=c,75,76,6,13,24,29,30,31,36,38,42,62&season=2016&month=0&season1=2010&ind=0&team=0&rost=0&age=0&filter=&players=0&sort=4,d Joe Kelly is very similar. Jarred Cosart doesn't throw quite as hard but his K/9 is even lower (though he has over-performed his peripherals). If I had to guess just quickly looking at these numbers, I would posit that one of the issues with Peralta, Kelly, etc. is that they throw hard but their secondary stuff isn't as good. It seems that the guys who throw >65% FB tend not to do that well (except Gerrit Cole, who presumably just has a good enough fastball to get away with that), probably because major league hitters are going to figure you out sooner or later.