In-Zone Whiff Rate Leaderboards and League Averages
Is there a better pitch than a pitch that can get great whiffs per swing inside the zone? If they don’t swing, it’s a strike anyway.
To that end, and also in order to supplement my work in trying to identify pitches that would be better used as strike-stealing pitches (in the mode of Erasmo Ramirez and his slider), I ran a few leaderboards that might be interesting to you, the reader.
Here are league average in-zone and overall whiff rates by pitch type. Obviously, breaking balls have the biggest difference, since many in-zone breaking balls are ‘hung’ pitches that failed to break like they should have.
| pitch_type | All Whiff | Zone Whiff | Diff |
| Knuckle Curve | 31% | 10% | 22% |
| Curve | 30% | 13% | 17% |
| Slider | 32% | 15% | 17% |
| Forkball | 37% | 22% | 15% |
| Splitter | 30% | 14% | 15% |
| Fastball | 28% | 15% | 13% |
| Changeup | 29% | 18% | 11% |
| Eephus | 15% | 6% | 9% |
| Cutter | 20% | 13% | 7% |
| Two-Seamer | 12% | 8% | 4% |
| Sinker | 12% | 8% | 4% |
| Four-seamer | 16% | 13% | 3% |
| Knuckler | 20% | 19% | 1% |
Zone Whiff = Whiffs/Swing on pitches in the zone
Looks like the knuckle ball is the same no matter where it ends up, although that pitch type suffers from a bit of a small sample problem — only the Eephus and Forkball pitches had smaller samples.
In order to compare different pitches when it comes to the ability to get whiffs on pitches inside the zone, you really want to adjust for pitch type, or all the knucklers and sliders will rule the roost. Here’s a fun leaderboard for adjusted in-zone whiffs on pitches thrown by starting pitchers.
| Name | Pitch | All Whiff% | Zone Whiff% | zWhiff+ |
| Chris Sale | FT | 25% | 18% | 224 |
| David Price | FT | 18% | 17% | 215 |
| Chris Heston | CU | 42% | 27% | 210 |
| Alex Wood | FT | 17% | 16% | 199 |
| Hector Santiago | SI | 17% | 15% | 189 |
| Clayton Kershaw | CU | 41% | 24% | 189 |
| Alex Wood | KC | 35% | 18% | 186 |
| Marco Estrada | CH | 34% | 33% | 180 |
| Carlos Carrasco | SL | 41% | 27% | 174 |
| Scott Kazmir | FT | 17% | 14% | 168 |
Zone Whiff = Whiffs/Swing on pitches in the zone
zWhiff+ = (Zone Whiff divided by league zone whiff on that pitch type) * 100
In related news, Alex Wood needs to throw his his knuckle curve and sinker in the zone more, it seems. He gets nearly twice the whiffs per swing on those pitches in the zone than other pitchers!
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.
Sale leads this list with a pitch he throws more than half the time. Dude’s stuff is just unfair.
Well, when you saw the title of the post, you probably figured Sale would be at the top of the list.