Baseball analysis often wanders from place to place, speeding up and slowing down. Sometimes you can find yourself tumbling into a wormhole.
One example is a series — What Makes a Good Changeup? — that I’ve worked on sporadically for most of this season.
Long story made short: When it comes to throwing change-ups, ground balls and swinging strikes are the most desirable outcomes. No matter which goal a pitcher pursues, getting some “sink” or “tilt” on a change-up is a good thing. The speed of the pitch is something else, and a bit of a conundrum.
To miss bats with change-ups in the Major Leagues, you typically need an above-average fastball and a big gap between your fastball and change-up. A pitcher with a slow fastball or a relatively firm change-up seems best suited for earning ground balls. Of course the best of both worlds is ideal.
Another way to put it is a little more negative. If you can’t speed up bats with your fastball, the guys in the big leagues will be able to adjust to your change-up. But therein lies opportunity: the ground ball. Throw a firmer and more sinker-like change-up and the results will come, but on the ground.
There’s more than a little wiggle room, just as there are many ways to pitch and be effective. The ideas described so far are useful measuring sticks, a way to gauge what kind of change-up a pitcher has.
You’ll have whiffers and worm killers, guys who do both and guys who do neither. You want someone with above an above-average rate in at least one category, whether it be swinging strikes per swing (Whiff) or ground balls per ball in play (GB).
The double threats show up in the top right of this chart, while the non-threats show up on the bottom left.
Stephen Strasburg and Gio Gonzalez have the double-threat change-up when looking back over a couple years. Strasburg is not just a double threat, but arguably the owner of the best change-up in baseball.
What about simply looking at 2013? The MLB averages for whiff and ground ball rates for changeups in 2013 are 31 percent and 50 percent, respectively.
The following table summarizes fastball speed (FB MPH), the gap between the fastball and change-up speeds (SPD GAP), the whiff rate on change-ups (CH WHIFF), the ground ball rate on change-ups (CH GB) and the “type” of change-up based on the above chart. The type is a rather crude measure, unfairly grouping guys who actually fall close to average. But who said anything about fair?
|Pitcher||FB MPH||SPD GAP||CH WHIFF||CH GB||Type|
|Erik Davis||93.6||8.2||35%||67%||double threat|
|Gio Gonzalez||93.3||8.8||40%||60%||double threat|
|Dan Haren||89.6||5.3||24%||46%||no threat|
|Taylor Jordan||92.7||8.9||38%||52%||double threat|
|Nathan Karns||94.1||7.8||27%||50%||no threat|
|Ian Krol||94.2||9.0||24%||46%||no threat|
|Ross Ohlendorf||92.9||9.9||19%||45%||no threat|
|Henry Rodriguez||97.7||7.9||41%||80%||double threat|
|Drew Storen||94.6||6.8||40%||53%||double threat|
|Stephen Strasburg||96.1||7.3||50%||64%||double threat|
|Jordan Zimmermann||94.6||6.8||19%||48%||no threat|
A note on Haren: Whiff rates and ground ball rates on his splitter have both improved since coming off the DL. He’s taken some speed off the pitch and changed the movement a little bit–the pitch now has more drop and seems to cut rather than fade — and the results are starting to show up. He’s still below average on both measures, but at least he’s moving in the right direction.
Krol, Karns and Zimmermann all seem to have enough velocity and speed gap to miss more bats. Zimmermann’s sample size is substantial, so the “that’s interesting” is louder for him than the two part-time relievers.