There was plenty about Clayton Kershaw’s Opening Day start that was predictable. He sat between 92 and 93 on that straight, riding fastball. He showed command of the pitch and didn’t walk anyone. He threw a fastball on his lone 3-1 count. The box score says he threw 27 sliders and got five whiffs — an excellent rate. His 15 curves got two whiffs and two outs on five swings. So a lot of Monday’s start was just vintage Kershaw. But that doesn’t mean he didn’t show us something a bit different.

Once he got the big lead against the Padres, out came a pitch he’s joked about working on for 10 years. Take a look at his horizontal movement against his velocity, and at least a couple dots on the plot stand out.

The raw PITCHf/x data doesn’t indicate that Kershaw threw any changeups against the Padres, but see those 85 mph pitches with arm-side movement? That’s what those are, most likely. And there’s a dot or two above them between 85 and 90 that might be changeups, too. According to Brooks Baseball, Kershaw threw only six changeups all of last year. Now it’s possible he’s thrown nearly that many on Opening Day. This requires further investigation.

There are four pitches that featured notable arm-side movement and traveled between 80 and 91 mph. Let’s order them by how impressive they were.

Fifth inning, 2 outs, 0 on, 0-1 count to right-hander Christian Bethancourt, following a 94 mph four-seamer. This one went 84 mph with 6.9 inches of fade compared to his fastball.



Sixth inning, 2 outs, 0 on, 0-1 count to right-hander Wil Myers, following a 71 mph curveball. This one went 86 mph with 4.8 inches of fade compared to his fastball.



Second inning, 0 outs, 0 on, 0-0 count to right-hander Austin Hedges. This one went 91 mph with 4.6 inches of fade compared to his fastball.



Sixth inning, 0 outs, 0 on, 0-0 count to left-hander Travis Jankowski. This one went 91 mph with 3.4 inches fade compared to his fastball.



Okay, let’s handle the latter two pitches first. One was thrown inside to a lefty (Jankowski), and though there’s some evidence that pitchers are going same-handed on changeups more often, the pitch itself isn’t in a location that normally features changeups. And it doesn’t really look like a changeup, even if it has more arm-side movement than his usual four-seam. Maybe he’s throwing a two-seamer? That pitch against Hedges also looks more like a two-seam fastball than a changeup. So probably nothing to see here.

Still, the other two pitches are characteristic of a real changeup. Which is strange, because (as noted above) Brooks Baseball said he threw six all of last year. It’s noteworthy that Kershaw threw even two of them in one start. Last year, he did that once against Atlanta in April and once before that, against the Padres (!), in his Opening Day start (!).

As for the pitch itself, it’s a reminder that we should define pitches off of the fastball rather than intrinsically. That good changeup had almost eight inches less drop than the average changeup from a lefty. It also had an inch less fade than your average lefty change. But if you compare those to his straight, riding fastball, it had nearly three inches of drop and six inches of fade — numbers that are just a little below average and almost twice average, respectively.

If Kershaw adds a changeup that looks like the one against Bethancourt, batters are screwed. He’s already proven that his breaking-ball mix can get righties out, but they’ve still managed a tiny platoon advantage against him, averaging a nutty-low .255 weighted on base average, still higher than lefties’ .239 wOBA. A changeup could neutralize the only advantage they’ve got.

By results, Kershaw had the best slider thrown by a starter last year, a top-10 curveball, and a top-15 four-seamer. Imagine adding a plus changeup.

Maybe Kershaw has made it a tradition to treat Opening Day starts against the Padres as extended Spring Training starts, or maybe the changeup is just in his head from all that spring work. From the second changeup, we can tell it’s still a work in progress. But, if you’d like to dream about dominance like we’ve never seen, replay that changeup to Bethancourt again.

In fact, let’s end on that note:

