Last week, I saw Dodgers lefty Clayton Kershaw in person for the first time. While he’s no longer the dominant force of nature he was at his peak — Kershaw’s fastball now sits 89-91, rather than sitting 92-94 and touching 97 as it did 2015-2017 — he’s still a very effective big league starter, on pace for a 4 WAR season, and the owner of a 3.51 xFIP across just under 100 innings pitched ahead of the All-Star break.
This is far from the first piece on this website to chronicle what makes Kershaw great as, over the last decade, he’s improved his command, and altered his pitch mix and pitching approach. What I suggest today is that part of his continued success also has to do with, simply, how he releases the baseball, and that this trait is identifiable in prospects.
It’s probably obvious to you that things beyond mere raw velocity contribute to fastball effectiveness. You can probably deduce what some of those things are through simple pattern recognition; the System Summary from this prospect list is an example of that. From having done this for a while now, there are common, visually identifiable characteristics shared by pitchers whose strikeout results outperform what we might anticipate given just their velocity, just as there are common mechanical/stuff-related attributes targeted by successful teams in the draft. (Those teams have also made mechanical and/or approach alterations to players they’ve acquired.) Spin rate, extension, vertical and horizontal approach angles, and spin direction/efficiency all play a role, too, as does command.
The more those traits serve to support vertical movement — a.k.a ‘rise’, life, carry, Z-break — the more swings and misses a fastball tends to generate. And when a fastball exhibits several of these traits, you can end up with a dominant heater despite limited velocity. Without them, I’ve been bamboozled by otherwise visually pleasing stuff. And indeed Clayton Kershaw’s fastball has some of these attributes. At 88-91, his fastball is still fine. In the mid-90s, it was utterly dominant.
The way we talk about these traits in scouting and player development is not yet entirely consistent across baseball. I was on the phone with an in-office analyst last week discussing what would eventually become this article, and we were using the same terms to describe different things, which caused us to argue for about 10 minutes before we realized we were simply miscommunicating. This video and these two articles provide a great foundation for understanding how pitches need to spin in order to create vertical movement. The version that has been most intuitive for me is the Rapsodo/TrackMan version, which describes spin direction by using a clock face from the pitcher’s perspective. The closer fastball tilt gets to 12:00, the more backspin it has. For the purposes of this article, I’m just looking at lefties, but you’ll be interested to know that some frequently-asked-about prospects like Zac Gallen (12:30 spin axis on the fastball), Astros RHP Jose Urquidy (91-95, up to 97, plus changeup and command, smart breaking ball usage, a 12:30 spin axis on the heater), and Ashton Goudeau (90-93, also has 12:30 spin axis, plus split/change) have some of the traits I’ve talked about.
It’s fair to watch a pitcher’s arm angle and assume that vertical arm slots create the kind of backspin we’re looking for, but we can better see the ball/hand relationship, including sub-optimal ones, using our high-speed camera, Slomie. If you didn’t read the Driveline and Laurila background articles, we’re looking for something close to pure backspin and seam uniformity. You’ll be unsurprised to see Clayton Kershaw exhibit both. At peak, he was averaging over 12 inches of Z-break on his fastball. He’s closer to 10 inches now, which is still above league average:
Spin rate is a factor here, too, and we have those for most of the minors. So based on information we have, here some lefty pitching prospects who I think also exhibit some of these Kershawian traits. I don’t anticipate any of them becoming as incredible as Kershaw, but they do possess mechanical characteristics that will enable them to get the most out of their stuff. Full scouting reports for most of these players can be found on THE BOARD.
MacKenzie Gore, San Diego Padres
Gore has all the components: the velocity, the spin axis, the seam uniformity, elite athleticism, some natural mechanical deception. He doesn’t spin his curveball as well as Kershaw, but his changeup is better. He’ll be in Sunday’s Futures Game.
Joey Wentz, Atlanta Braves
Wentz doesn’t have the quality breaking ball but his fastball plays well above it’s 88-91, and he has good changeup feel.
Ethan Small, Milwaukee Brewers
The Brewers 2019 first rounder is Kershaw’s mechanical doppelgänger. In 2019, he struck out 176 hitters in 107 innings for Mississippi State, most of them in the SEC, while sitting 88-92.
Joey Cantillo, San Diego Padres
Cantillo, a 2017 16th rounder out of a Hawaii high school, only sits about 88-92, but the life on his fastball and the quality of his secondary stuff has him missing lots of bats in the Midwest League. He hasn’t allowed more than one run in a start since April 26.
Tarik Skubal, Detroit Tigers
Skubal’s full report is on The Board. He ranks 14th in the minors in swinging strike rate.
Erik Miller, Philadelphia Phillies
He doesn’t get into his legs the way Kershaw does, and the velocity fluctuations Miller has experienced over the last year and a half is a bit concerning, but he has the pitch specifications I’ve outlined above and knows how to mix his stuff.
Burl Carraway, Dallas Baptist University
I anticipate Kiley will have high speed of Carraway in the coming days, as he’s been electric for Team USA recently, up to at least 97 with a knockout breaking ball.
Drew Dowd, Junipero Serra HS (CA) and Ross Dunn, Cottonwood HS (UT)
These were the two high schoolers at PG National whose fastballs I thought played up above their velocity for the reasons I’ve outlined above, though Dowd might be better off working with a four-seamer.
Eric Longenhagen is from Catasauqua, PA and currently lives in Tempe, AZ. He spent four years working for the Phillies Triple-A affiliate, two with Baseball Info Solutions and two contributing to prospect coverage at ESPN.com. Previous work can also be found at Sports On Earth, CrashburnAlley and Prospect Insider.