With A Drop In Arm Angle, Hughes Throwing A Sinking Four-Seam

It’s no secret that Yankee Stadium is a known for it’s small dimensions, it’s shallow right field porch, and its gritting relationship with right handed fly ball pitchers. knows, and his career 12.3% HR/FB in Yankee Stadium contrasts with a 7.1% on the road. It wasn’t too long ago that I questioned the organization’s philosophy on pitching, wondering why Yankee pitchers seem to add cutters in pinstripes, when they should be concentrating on the sinker. The theory is that groundballs are more important in the small dimensions of Yankee Stadium than four-seam fastballs and cutters, that while induce strikeouts, are much more prone to flyballs and linedrives.

“Without getting too far into it,” A.J. Burnett explained, “I would just say I let a few too many people tinker with me and when you let that happen, you get out there, you start doubting yourself sometimes, like, ‘Am I doing it right? Is this the way it is supposed to feel?’”

During ex-Yankee pitcher ‘s tenure with the team, the Yankees gradually added a cut fastball to his repertoire. The Pirates’ response to this was to lose the cutter, and double the usage of the sinker to 30% selection. The results have reflected on his 3.32 ERA, but even more so on his 55.5% GB rate, which is now the second highest of his career. If the Pirates wanted to cut down on his flyball rate inside one of the least homerun prone parks in the game, why wouldn’t the Yankees try this?

Phil Hughes once explained why he didn’t throw a sinker, and stated that he never developed a feel for the two-seam fastball in the minors. Of course, Hughes has found ways to adjust without it all season long, including lowering his arm slot a few inches. The goal was to create more sweeping action into left handed hitters with the curveball, but the results have included an overall increase in his spin angles on all his pitches.

As expected, the lower arm angle created a higher spin angle for the four-seam fastball. Before the drop, Hughes averaged a spin angle of 205 degrees, but between the last two starts, he’s between 218 and 219. So why is this important? Although a two-seam fastball and four-seam fastball differ on how they are thrown, in terms of PITCHf/x identification, a four-seam fastball is typically thrown between 200-220 degrees from a right hander, while a sinker is thrown from 220-240 degrees. Throughout Hughes’ career, his four-seam sat very close to the 200 degree mark, creating a powerful rising fastball, but recently that number is sitting closer to the typical 220 degree sinker spin.

With the higher spin angle, the movement from the four-seam shows the expected decrease in the vertical movement, and an increase in horizontal movement into right handed hitters. The movement over his last two starts is very close to that of a sinker. Without that rising action, Hughes saw less whiffs, but he also saw an increase in groundballs and a decrease in flyballs. Over the last two games, his flyball rate on the four-seam is only 33% to righties and 16.7% to lefties. The sample size is very small, but those results are typical for this new pitch movement.

In the end, Hughes isn’t throwing a sinker, but his four-seam is acting like one. It’s possible Hughes keeps this up and finally becomes a groundball pitcher. Considering his bread and butter has been whiffs on the rising four-seam, it’ll be an interesting experiment if he continues to throw a sinking four-seam. Can the groundballs outweigh the strike outs in the end?