Mariano Rivera is famous for being a one-pitch pitcher. He's the most dominant reliever of all-time, thanks to a ridiculous cut fastball.
Kenley Jansen is following in Rivera's footsteps, specifically with the cutter. He's throwing it 94.6 percent of the time this season, according to Brooks Baseball.
When a relief pitcher has such a dominant pitch as Rivera and Jansen, it's not surprising to see them throw that pitch almost exclusively. But those pitchers are rare.
Paco Rodriguez has a nice three-pitch mix, but he's throwing his 4-seam fastball just 20.8 percent of the time this season. In his brief 2012 debut, he threw his fastball 41.6 percent of the time. The scouting report on Rodriguez out of college was his fastball sat in the low-90s. In his brief career, he's averaging exactly 90 MPH on the pitch -- the lowest of the 90s. He's resorted to his cutter and slider much more than his fastball this season, which isn't necessarily a bad thing. Rodriguez is throwing his...