Cole’s Cutter

During the off-season, Phillies pitcher Cole Hamels made an effort to become a new type of pitcher, opening his arsenal to more weapons in hopes of sustaining long-term success. He decided to incorporate a steady serving of curveballs and cutters into his healthy diet of fastballs and changeups, and so far the relatively superficial stats seem to be generally supportive of the process:

2008: 3.72 FIP, 3.63 xFIP, 4.26 tERA, 7.76 K/9, 2.10 BB/9
2009: 3.72 FIP, 3.69 xFIP, 4.15 tERA, 7.81 K/9, 2.00 BB/9
2010: 4.21 FIP, 3.66 xFIP , 4.38 tERA, 8.94 K/9, 2.98 BB/9

After a career-low walk rate last year, Cole has dropped to a walk rate worse than as any season since his rookie year by a significant margin. Still, his strikeouts are way up and it seems that his biggest issue in terms of performance has been the quality of his balls in play. His HR/FB rate is at a career-high 14.6%, as Cole has given up more homers per fly than the average pitcher each year in the big leagues. His groundball rate, however, is a career-high at 44.1%, but that may have more to do with a LD rate of 18.1%, which is as low as it has been since 2006.

But our run value charts show that Hamels’ cutter has been a bad pitch for him, coming in at -4.3 RAA, compared to 5.3 for his fastball and 3.1 for this changeup. His curveball has been basically an average pitch at -0.1. Pitchf/x guru Harry Pavlidis at The Hardball Times discussed Hamels’ new repetoire and did a fantastic job breaking down the lefty’s performance in a two-part series using his rvERAa and rvERAe stats, eventually concluding:

-An increased rate of flies and liners turning into home runs is observed when Hamels adds a fourth pitch heavily to the mix. Coincidence?

-While the fastball and sinker may or may not have been compatible, the cutter and the fastball may be

-The jury is still out on the cutter, but the sinker is welcome to stay away

-His change-up is very good, it’s a shame it’s used less and less

-His curveball I can take or leave. As a commentor noted in part one, it’s more of a show-me pitch than anything

My vote: keep working on the cutter, but have some more faith in the change-up.

Using the Bloomberg Sports Pro Tool, I wanted to take a look specifically at Hamels’ cutter, which Harry suggests he should tune up even though the metrics say it has stunk. Here’s a look at the forty-seven cutters Hamels has thrown to lefties this season along with their corresponding location in play if they were hit for an out/base:

As you can see, Hamels has thrown his cutters mostly away to lefties in the limited time he has tried it, and so far the results are good. Lefties have yet to get a hit against the pitch, either grounding out or flying out each time. But here are the images for right-handed hitters:

Righties are simply crushing Hamels’ cutter this season. He’s thrown it 120 times against them in 2010, and thus far they’re hitting .412/.429/.882, which simply will not get the job done. His cutter has also averaged 88.8 MPH to righties while only 88.1 MPH to lefties, so it may just look and act like a flat fastball to righties, who have taken advantage of it. As you can tell from the last image, his HR/FB rate on the year has clearly taken a hit due to his cutter versus right-handers.

I agree with Harry’s ultimate conclusion that Hamels should continue to work on his cutter. But until Hamels has a firm grasp of it, he should toy with it versus lefties and only versus righties in games with an extremely low leverage index (i.e. big leads). Until then, it will continue to get hit far.