Data Dump the Second: Relievers


During the holiday dead zone (the space between Christmas and New Years aka Taint Week) Getting Blanked rolled out a post graphing starting pitchers by a version of their FIP components. Certain clumps emerged, demonstrating the skills and abilities separating aces from middle rotation guys and inning-eating scum from barely employable dirt bags.

The post generated a fair amount of discussion, which is always a good thing. So why not dump some more data: this time with relief pitchers!

This charts all relievers with 150 IP over the past three seasons, which is a much lower threshold than starters. Relievers are erratic and there is a great crop of young guys who wouldn’t qualify if we raised the experience bar too high.

As before, the x-axis is strikeout differential (K%-BB%) and the y-axis is home run per ball in play. Might relievers feature a different skill spread than their starting compatriots?

First thing to notice: the averages shifted slightly for relievers. The average K-BB% rises to 12.88% from 10.5% and the home run per ball in play average down to just over 3%. Whether this speaks to the greater impact of suppressed 2011 run environment weighing more heavily in a smaller sample size or the relative quality of relievers good enough to pitch 100 innings, I can’t say. Just keep it in mind.

There seems to be a great cluster of pitches in the “good” quadrant for relievers rather than starters, speaking to the nature of their job and the selection bias inherent in relief pitchers. Entering games during high-leverage jams, throwing max effort innings in which strikeouts are key – situations which allow for the type of wiggle room “pitch to contact” players require.

One note on the gigantic point without a name: this pitcher actually just missed the innings cutoff, with only 97.2 innings over the past two years. The dominant nature of his performance demanded his inclusion though I excluded his name. First person to guess in the comments wins a (probably terrible) prize. Here’s a hint: it is incredibly obvious!

If you have any questions about your favorite relief ace’s placement: let me know. We had a good time sifting through the results the last time, let’s do it again!

Stats courtesy of Fangraphs, without whom I’m nothing.