clock menu more-arrow no yes mobile

Filed under:

What's Gotten Into Trevor Cahill?

No, really, what's happened to him?

Now, I'm not going to consider any of this set in stone, because there's always a real possibility that the PitchFX cameras in Toronto were miscalibrated. But take a look at his movement chart from last Friday's start. (Click for a bigger version.)


To reiterate, this graph shows every one of Trevor Cahill's pitches and their movement, from the point of view of the catcher. A pitch at (0,0) where the axes cross would represent a perfectly spinless ball, only affected by gravity. I did something a little different this time around, and colorized each pitch based on velocity. Pure red was set at his fastest pitch, and pure blue represents his slowest. Rather than use color as pitch identification, I just roughly circled different pitch groups.

For comparison, take a look at some of his movement charts from last year. Unless the cameras in Toronto are completely out of whack, Cahill has made some serious adjustments after last year's terrible campaign. He's exhibiting a very large increase in sink among all of his pitches, ranging from an inch on his fastball to three on his sinker and five to six on his brand new curveball. For a sinkerballer, increased sink is always a good thing, as it leads to more groundballs.

Of course, last Friday's start didn't exactly go very well for Trevor. It looked to me like much of his troubles came from pitch location, rather than movement. He was constantly leaving balls up in the zone, which is a huge no-no for any sinkerballer who relies on groundball outs. Much like Brad Ziegler, if Cahill is allowing fly balls and home runs, something is wrong.

Every Trevor Cahill scouting report I've read made special mention of his "heavy" fastball, with some calling it "toxic" and "deadly". If he can control this increase in sink and stop leaving balls up high, he should definitely be in line for some improvement on his dismal 2009 season.


Odds and Ends

  • All of the talk during the offseason about his new curveball and I didn't end up talking about it much. A lot was said before this season about Cahill ditching his knuckle curve in favor of a new spike curve. It shows. His new curve comes in at around the same speed as the old one (80 mph) but has a much more pronounced break to it. Like I said earlier, it falls five to six inches more than his old one.
  • I drew a big circle around a mess of pitches that I labeled "Changeup/Slider". I really wasn't sure what to call them. PitchFX was about as confused as I was. Changeups usually sit a little north of where his sinker sits on the chart, and sliders tend to be above and to the right of my big circle, in the first quadrant. We'll see, I suppose.
  • How's the new coloration and pitch identification method in the chart? Good? Bad? Is it more clear? That "Changeup/Slider" labeled mess would have been difficult to work with otherwise.
  • Completely off topic, but Beyond the Box Score is running a guessing contest, where the winner gets 50 bucks. All you have to do is guess which answer is numerically larger. It's Beyond the Box Score, so many of the questions are sabermetrics-based (e.g., Franklin Gutierrez's UZR+PosAdj or Adam Dunn's UZR+PosAdj, times -1?), but many of them are doable without any stats knowledge at all. Entries are due by Friday.