Updated benchmarks for pitch types

Last May we took a look at how each different type of pitch thrown in the big leagues fared on a variety of metrics. This year’s data set goes beyond a couple months of play and includes 2010-2011 (as of last week). We’ll forgo the “rvERA” metrics as those are being rebuilt. A never-ending process.

All classifications are my own, so if I didn’t classify it myself, it’s not in the mix. As noted last year, these classifications are not perfect but have expanded and improved over the past 12 months. Strike zone tops and bottoms are now based on a combination of PITCHf/x stringer data and player height. “Chase” and “Watch” use the new top/bottoms and the rulebook plate width (.83 feet to either side of center) while IWZ uses the same tops and bottoms but a “plate” that stretches a total of two feet across.

Key

 
Type = pitch type
# = number thrown
MPH = speed at release, 55 ft. from the back end of home plate
Swing = swing rate (swings/pitches)
Whiff = whiff rate (misses/swings), includes foul tips
Foul = foul ball rate (fouls/swings)
B:CS = umpire called ball-to-called strike ratio
IWZ = rate of pitches thrown within a "wide" strike zone
Chase = swing rate outside of the wide zone
Watch = take rate inside of the wide zone (inverse of swing rate)
nkSLG = non-K slugging, or SLGCON
GB% = rate of balls in play tagged by MLBAM stringers as grounders
LD% = line drives
FB% = outfield fly balls
PU% = infield fly balls
HR/FL% = home runs per outfield fly + line drive
CH = Change-ups, may include some splitters that tail more than tumble
CU = Curveballs, probably some slurves
SI = Two-seam fastball, sinkers, tailing fastballs
FA = Four-seam fastball, generic fastballs
FC = Cutters and some slutters, can be a fuzzy group
FS = Splitters, foshes and forkballs, may include some other tumbling change-ups
KN = Knuckleballs, although some of Eddie Bonine’s (et al.) are not in here
SB = Screwball, sole property of Danny Herrera 
SL = Slider or slurve, even some slutters

First, the bottom line taken from all of the included pitches:

Now by individual type:

Since classifications of pitch types can overlap or be imperfect, it’s helpful to group pitches together. One approach is to combine cutters and sliders to make slutters, sliders and curves to make slurves. Not safe at the individual level, but informative otherwise. To limit confusion, we’ll spell out the pitch names and mark the combined types with *.

The same process gets us a generic fastball. We could include cutters here, but let’s try and stick to the hardest thrown stuff.

Last and certainly not the least, off-speed pitches.

A combined set of breaking pitches can be collected. Since cutters were left out of the fastballs, they’ll stay with their breaking friends. Not a super-duper idea, but we’re going macro level here.

For the visual thinkers in the audience, here are some charts. Scaling is not controlled or constant, so it’s all directional/relative within a pane. The list of pitches in the middle are the ‘labels’ for each point (left-to-right).

I guess we’ll update these again next May, make it a tradition.

References & Resources
PITCHf/x data from MLBAM and Sportvision. Pitch classifications by the author. Batted ball data from MLBAM.