- FanGraphs Baseball - http://www.fangraphs.com/blogs -

Contrasting Bullpen and Rotation Velocity

The glorious juxtaposition of the Red Sox starting Tim Wakefield and relieving him with Daniel Bard or Manny Delcarmen was never lost on me. Moving from a pitcher with an unplugged heater to a live arm with a fireworks shooter attached in place of a right arm is one of the weirdest sights around. How hitters manage to adjust in such a quick manner is a testament to their talents. Are there any teams that go from Bards to Wakefields though? The very thought of which drove me to find out just which rotations throw harder than their pen friends.

As it turns out, they do exist, all three of ‘em root from newly minted franchises. Allow me to procrastinate before introducing the results by hand-waving the usual caveats associated with pitch speed data. My hope is that since all comparisons are inner-team, most of the noise from pitching in different ballparks and with various pitch scorers cease to be an issue. For more information on just how much velocity readings can vary by park, I highly encourage Mike Fast’s piece here. Tom Tango left an interesting comment that sort of applies here, too; you’ll see why almost immediately.

To the methodology. I simply went to the team leaderboards and pulled the average fastball velocity for each team’s rotation and bullpen, then subtracted the rotation velocity from the bullpen velocity. The numbers in this post originally came out as negatives, but I absolute-valued those mothers so as to make everyone more comfortable. To the results.

Marlins: 0.6 MPH

Josh Johnson throws hard (94.9 MPH). So hard that he leads the Marlins among qualified pitchers in velocity, just ahead of a number of bullpen arms, like Jose Veras (94.3), Leo Nunez (94.0), and Tim Wood (92.9). So, how then is the Marlins’ rotation tossing hotter pebbles than their pen? Because of Nate Robertson (87.8), Brian Sanches (88.4), Clay Hensley (88.6), and Burke Badenhop (88.7). The rest of the Marlins’ starters are consistent in their heat, sitting between 92 and 91 MPH.

Rockies: 0.7 MPH

Ubaldo Jimenez (96.2), Esmil Rogers (94.4), Jorge de la Rosa (93.4), and Jason Hammel (93.1) make this one easy to understand. Outside of Franklin Morales (94.4), no other reliever with at least 30 innings pitched would top any of those aforementioned starters. One can only contemplate how different the figure would be without Greg Smith (86), Jeff Francis (87.2), and Aaron Cook (89.5) weighing down the rotation’s average velocity.

Rays: 1.6 MPH

I should have known the team I am most familiar with would lead the league. David Price (94.6) and Matt Garza (93.3) feature two of the most explosive fastballs in the league. The bullpen, meanwhile, consists of an army of feather ticklers: Andy Sonnanstine (86.6) and Lance Cormier (88.6) who rack up pitches and mop up innings alike, as well as the interchangeable set-up specialists Randy Choate (87.2) and Dan Wheeler (88.6). Joaquin Benoit (94), Rafael Soriano (92.9), and Grant Balfour (92.7) do their best to make opposing batters feel the heat rise during the final frame.

Later, the teams with bullpens that significantly overpower their rotations.