The Mechanical Change That Maybe Brought Jon Lester Back

You’ll hear some superlatives sent in Jon Lester’s direction after a couple of strong performances in the World Series. The All-Star break — when Lester was sporting a 4.58 ERA and velocity readings that didn’t inspire hope — seems like a long time ago. Between then and now came a mechanical change, and maybe a short rest, that brought the old Jon Lester back in time for this great postseason run. Remarkable about that fact, though, is that the change has been a long time coming.

As early as last year, people were noticing that there was a need for change. Michael Barr wrote about Lester’s cutter, and its lack of cut:

Based on the behavior of the pitch, that is, the kind of movement he’s getting — it does seem to support that he’s throwing fewer cutters and more sinkers. And in fact, the cutters that he has thrown in 2012 have demonstrated less horizontal movement than they did in 2011, behaving much more like his regular fastball. He tosses in a curve and a change about 13% of the time each, but that’s pretty consistent with years past. The big change appears to be a reliance on the sinker at the expense of the cutter.

That post appeared on August 12th, 2012. Since that day, his cutter use has indeed gone up, back up to 16.1% this year after sitting closer to ten percent for much of 2012. But using the pitch more did not immediately lead to better life right away.

Going into the season, Jeff Sullivan collected some notable mentions of mechanical change. Sort of like Craig Calcaterra’s Best Shape Of His Life posts, the idea was to go back and look when the season was done. (Sorry Jeff, I got this one.)

Here’s what Jeff found from manager John Farrell going into the season:

New Red Sox manager John Farrell and Lester both noticed some “clicks” in Lester’s delivery that set him off down the wrong path last season, particularly before the All-Star break. Lester, Farrell said, swung his lead leg “like a swinging gate,” with a collapsing backside. Those minor tweaks caused Lester to lose his downward angle, which helps with both pitch location and velocity, and his pitch deception.

“Last year wasn’t off by much. Honestly it’s a click,” Lester said. “That click can mean the difference of the angle. Your hand’s underneath it as opposed to being on top. Cutter flattens out. Curveball’s loopy. Just that click can make the biggest difference. We’re trying to fine-tune those things.”

Well, now we have to movement things to look for, since one referenced the cutter ‘flattening out’ and the other talked about horizontal movement. But look at Brooks Baseball’s charts for the vertical movement, and the cutter has stayed remarkably steady. “Flattening” can really refer to horizontal movement, too, and it’s in the x-movement that we might find some evidence of struggle:


Already the narrative is incomplete. We can see that Lester has struggled with his cutter movement from time to time, but those times don’t all march in time with the days that saw good results from the lefty. And we can see that Lester’s overall velocity increased in the second half, but that he still struggled with the cutter coming out of the extra rest he received over the all-star break.

So let’s just focus on his legs. We’re looking for a swinging lead leg and a collapsing backside. The one on the left is a clip from before the all-star break in 2012 (6/27/12 vs Toronto), a time period that Farrell refers to in particular. The one on the right is from his September third start this year against the Tigers, which came in that plateau of good horizontal cut late this season.


You can clearly see the ‘lead gate’ action on his front leg. And it certainly looks like his back leg is more upright when his arm begins forward to the plate, doesn’t it? Let’s freeze that moment, with early 2012 on the left again, and late 2013 on the right. Take particular notice of the angle between his calf and the mound, and the angle of his throwing elbow with respect to the ground. It looks like he’s ‘on top’ of the ball more, and his back leg is in a better position to drive forward.


Before the All-Star break, Jon Lester averaged 94 on his four-seamer in one game. After the All-Star break, he did it ten times. Velocities naturally peak in August, but this has continued well into October for Boston’s southpaw.

That new velocity, and greater cut on his cutter, might have something to do with something he noticed in 2012 and has been working on ever since. It’s just that hard for a pitcher to get all of his body parts moving in the right direction at the right time. And it’s also that hard for us to know when a player’s own words about the mechanics of his craft are signal or noise.

With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.

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Clint Callaway
10 years ago

Well done! This is certainly the best, most comprehensive breakdown and analysis of any/all the WS(ad nauseum)commentaries! The side-by-side graphics are so helpful in driving the message(and the cutter)home-great job!