This season, Major League Baseball rolled out their new Statcast program, complete with flashy new data such as batted ball velocity for hitters, route efficiency for position players, and even the spin rate in rotations per minute for pitchers. Thanks to Pitch F/X, around since 2007, we have access to the velocity, release point, and movement for every pitch in every game. Spin rates were also available, but Pitch F/X spin rates are not as reliable, as they are mathematically extrapolated instead of being measured on the spot.
Spin rate data has looked promising a season into its availability. Granular, pitch by pitch data is not available to the public, but each pitcher's MLB.com profile will feature Statcast data on one of his pitches, usually the one each pitcher is known for. Kenley Jansen's page features information on his cutter, while Masahiro Tanaka's page provides data on his splitter. Cleveland Indians starter Trevor Bauer owns a Trackman device, and is known to monitor the spin rates on his pitches when he throws in the offseason.
But while knowing how many rotations per minute each pitch gets is interesting, it might not tell the whole story. Take two very talented pitchers as example: Jacob deGrom and Carlos Carrasco. At first, their four seam fastballs look extremely similar. Here is some of the data on their heaters, provided by MLB.com:
|Player||Avg. FB Velocity||Avg. Spin Rate|
|Jacob deGrom||95.27 mph||2242 rpm|
|Carlos Carrasco||95.29 mph||2262 rpm|
For good measure, take a look at their similar arm slots, both from the vantage point of the cameras at Tropicana Field (every team should have this dead center camera angle, but that is a discussion for later):
That is where the similarities end. According to Brooks Baseball, hitters have a much better time hitting Carrasco's fastball:
Statcast might offer the answer to the disparity in their fastball success. They also measure each pitcher's extension, providing insight as to which pitchers have the longest strides toward the plate. According to MLB.com, deGrom's stride is about eight inches longer than Carrasco's.
Fastballs with a higher spin rate are not affected by gravity as much, giving them the "rising" effect often described by commentators. DeGrom, with an average spin rate, uses a long stride and a lower arm slot to confuse hitters. When scouts evaluate taller pitchers, they will often describe them as throwing with a downward plane, since their release points are higher. DeGrom is basically doing the opposite, using a deceptively flat plane to "cheat" his way to a high-spin fastball.
The kicker, though, is that Carrasco's two-seam fastball actually gets about three more inches of sinking action than deGrom's. It could be argued that since Carrasco's stride is shorter, his pitches travel a greater distance, and the forces of gravity have more time to affect the path of the ball.
From what we know so far, a high or low spin rate is something a pitcher either has or doesn't have, at least for fastballs. In an interview with Fangraphs, Trevor Bauer said he has been able to increase the spin rate of his sinker and curveball, but not his four seam fastball. In addition, pitchers presumably decide which arm slot to throw from based on what feels comfortable.
If this is the case, pitching coaches could have their pitchers play around with their stride lengths, using their spin rates and arm slots to put together a plan to optimize the usage of each pitcher's stuff. Pitchers with higher spin rates on their fastball might consider lengthening their strides to maximize the rising effect perceived by hitters. On the other hand, pitchers with lower spin rates could consider going for less extension.
By now, every Yankee fan is familiar with CC Sabathia's transition from a flamethrower to a sinkerballer. He gets a good amount of sink on his two-seamer, but hitters still managed to hit .311 and slug .514 against the pitch, according to Brooks Baseball. Interestingly, his Statcast-measured stride is one of the longer ones in baseball, at almost seven feet. If he were to shorten his stride, he might get even more sink and force hitters to hit for more groundouts. (Of course, we at Pinstripe Alley are rooting for the big man to successfully find the help he needs in his personal life before worrying about baseball.) With plenty of other pitchers in the minors who are on the cusp, the Yankees could have their Statcast data measured as well. If we are lucky, Statcast could change the way teams develop, optimize and manage pitchers.