scorecardresearch Skip to main content
Alex Speier

Trying to pinpoint the source of Chris Sale’s diminished velocity

Chris Sale delivers a pitch earlier this season.Matthew J. Lee/Globe staff file

It’s fine, it’s fine, it’s fine . . . maybe it’s fine?

That tone describes the Red Sox’ view of Chris Sale’s return to the mound this month, one in which the lefthander has not shown the same high voltage stuff that characterized his charged run through the summer. Since his return from a second stint on the disabled list due to left shoulder inflammation, Sale’s velocity not only has failed to match the career-high, high-90s stuff that he featured before his injury, but his average four-seam velocity has declined in each outing since his return. He averaged 90.1 m.p.h. with his four-seamer on Wednesday, the lowest fastball velocity of any outing of his career.


Sale insists that his shoulder is fine and that the issue relates to his lower body. Regardless of whether the issue is the shoulder or his legs and hips, however, the Sox and the pitcher alike are no longer trying to pretend that his diminished stuff isn’t a problem with seven days remaining before Game 1 of the ALDS.

“Hopefully,” said manager Alex Cora, “he will find his mechanics again and he will be ready to go.”

The use of the adverb “hopefully” is hardly an overwhelming declaration of confidence. There is a correction that the pitcher and the Red Sox must make. That said, the outlook is different if his issue is related to an ongoing shoulder injury as opposed to a mechanical glitch.

That being the case, it’s worth asking — is there anything in Sale’s pitch data that gives an indication about whether it’s his shoulder or lower body that’s responsible for his decreased velocity and power?

Sale’s average vertical release point (how far the ball is from the ground at the point or release) on Wednesday was squarely in the middle of his marks for the year. His horizontal release point (how far toward first base, relative to the center of the rubber, the ball is at the point he lets it go) likewise was within his normal range.


But what about his extension toward home plate?

Extension measures how far in front of the rubber the ball is at the point that a pitcher releases it. When batters talk about how it feels as if Sale is on top of them at the point of release, extension — which is dictated chiefly by lower-body mechanics — plays a part in that.

On Wednesday, Sale’s average extension at his release point was 5.97 feet toward the plate. That continued a pattern in which his extension in September has been relatively low (6.06 feet) as compared with his season average (6.11 feet), and particularly low relative to how close he’d been to the plate during his 10-start run of dominance.

From June 8-Aug. 12, when Sale had a 0.69 ERA with 109 strikeouts and 12 walks in 65 innings, he was releasing the ball 6.19 feet toward the plate from the rubber. Moreover, his followthrough with his left leg was particularly aggressive, carrying past his right (plant) foot and reaching almost the bottom of the mound — something particularly visible in his Aug. 12 start against Baltimore, when he struck out 12 in five innings while featuring his second-highest extension (6.28 feet) of the year.

Overextending issues The greater the extension, the better the results for Chris Sale
Period Average extension towards home when throwing four-seam fastballs
2018 season 6.11 feet
June 8-August 12 6.19 feet
September 6.06 feet
Wednesday 5.98 feet

On Wednesday, Sale’s delivery was far less aggressive. His left foot came down softly, almost adjacent to his right foot.


By itself, the two or three inches of extension wouldn’t necessarily have a significant impact — although the increased whip required to release the ball further out in front of the plate could have some impact on his velocity. The greater issue with diminished extension is that it can serve as an indicator of mechanics that have fallen out of synch. If a pitcher’s coordination of his legs and arms changes even slightly, the disconnect can have significant implications for a pitcher’s stuff, command, or both.

Sale’s key checkpoints are the position of his landing foot and the alignment of his shoulders and hips in a direction toward the plate when he gets to that landing spot. If any of that is off, a fix is required. Right now, the coordination of those events appears to be off.

With those mechanics, diminished velocity seemed like an almost inevitable outcome — particularly given that, with help from Statcast data available at, there does appear to be at least a modest correlation between Sale’s extension and velocity.

Moreover, Sale’s least dominant outings have typically come when his extension has been modest, while some of his best came when he was further toward the plate.

Wednesday marked the fourth game this year (also April 26, May 1, and June 1) in which Sale had an average extension on his four-seam fastball of less than six feet. Those outings yielded four of his worst 10 velocities this year — along with a 4.18 ERA and a relatively modest (for Sale) 24 strikeouts in 23⅔ innings.


The silver lining for the Sox? After a June 1 start in which Sale featured his second-lowest extension of the year (5.92 feet toward the plate) and one of his bottom 10 average four-seam velocities (94.8 m.p.h.), he received an extended period of six days of rest. When he returned on June 8, Sale’s extension was back at 6.12 feet toward the plate, and his velocity exploded, averaging 97.8 m.p.h.

Perhaps it is with that history in mind that Sale expressed optimism that a fix is possible with just over a week to prepare for a Game 1 start.

“We’ve got extended time now to kind of figure out what we need to do and we’ll go from there . . . Things like this happen. You get out of whack, and have just got to find a way to get back into that groove,” said Sale. “Once those lights flick on in October I’ll be there.”

But will it be vintage Sale? Is his lack of extension truly just his lower-body mechanics, or is it a reflection of the pitcher holding back to protect his arm?

Obviously, the Red Sox are hoping for the former — with the fallback possibility that Sale could adapt to a diminished arsenal thanks to a still-devastating slider.

That said, while Sale’s return from shoulder discomfort was done in a deliberate fashion meant to offer the Sox a sense of certainty, the lefthander’s entry into the postseason instead comes with an unanticipated element of mystery.


Alex Speier can be reached at Follow him on Twitter @alexspeier.