Last night, Jered Weaver continued his breakout season with a seven-inning, seven-strikeout, one-hit, no-walk win against Cleveland. Weaver has career-high strikeout rate (9.6) while maintaing a career low walk rate (2.2). His great season may have flown a bit under the radar because the Angles have been out of playoff contention for so much of the season, so I wanted to make sure to look into it a bit before his season ended.
Looking at pitch-type numbers, his curveball percentage has gone up a bit, and that prompted me to poke around regarding his curves. Just checking one game’s location charts, I noticed that a number of these curves were up in the zone, and that those high curves induced some whiffs. Usually curves are thrown lower in the zone, where they get the most whiffs.
Were these high curves (and whiffs on them) a one-day fluke or a pattern for Weaver? I plotted a histogram of the heights of his curves to see.
Looks like Weaver does consistently throw higher curves than the average pitcher. Does he get a fair number of swinging strikes on them? (Bands around the line are standard errors of the estimate.)
It looks like that is also the case. His curves up in the zone, and above the zone, induce about 10% swinging strikes while the average pitcher’s curves up there induce under 5%. On the other hand, Weaver’s curves below the zone induce less than 15% swinging strikes, while the average pitcher can induce around 20% swinging strikes.
All of Weaver’s pitches tend to be up in the zone — he is routinely among the league leaders in FB% — so maybe he succeeds with a high curveball because of how it looks to the batter relative to his high fastball. Josh Kalk has an interesting post on curveballs following high fastballs. It would be cool to repeat such an analysis based on the height of that curve.