A fastball is a pitcher's bread and butter, whether he is a starter atop a team's rotation running through the opposing lineup multiple times or a high-octane reliever trying to slam the door with a handful of outs late in the game.

Even pitchers who are better known for a signature offspeed pitch are generally only able to enjoy so much success with their secondary pitches because they can set things up with their fastball.

Ahead, we have selected the best fastball on each MLB roster, based not simply on radar gun readings, but digging deeper into secondary metrics like expected batting average (xBA), expected slugging percentage (xSLG), strikeouts, whiff rate and usage rate of each player's fastball.

It's difficult to make a one-to-one comparison between four-seam fastballs and other pitches like sinkers and cutters, so along with recognizing the best fastballs, a quick nod is also given to the best sinker and best cutter on each MLB roster.