Take a quick glance and you might not be particularly encouraged by what Clayton Kershaw has done since returning from the disabled list.
There’s nothing wrong with a 3.32 ERA, but Kershaw hasn’t finished with an ERA that high since he was a rookie. You’d be tempted to think Kershaw’s under-performance is one of the reasons the Dodgers are looking up at the Giants in the standings.
But we can go deeper than this. For one thing, it’s worth acknowledging Kershaw’s one disastrous start against the Diamondbacks. This is bad analysis, but if you forgive Kershaw for a bad day, his ERA drops from 3.32 to 1.94. He’s been outstanding, except for once.
And we don’t even need to mess around with ERA anyway, since we have more meaningful numbers at our disposal. If you believe what the numbers are saying, Kershaw might’ve somehow improved. It all comes out of the following foundation: the very best pitchers get strikeouts, limit walks, and limit homers. In order to limit homers, it’s preferable to limit fly balls.
There are 114 starting pitchers who have thrown at least 40 innings this year after throwing at least 40 innings last year. Kershaw is among 62 of them who have improved their groundball rates at least one percentage point. Out of those guys, Kershaw is among 25 who have also improved their strikeout rates at least one percentage point.
Out of those guys, Kershaw is among nine who have also improved their walk rates at least one percentage point. Out of everybody, Kershaw’s walk-rate improvement ranks 21st. His strikeout-rate improvement ranks 12th. His groundball-rate improvement ranks third. Already silly, Kershaw’s more advanced numbers have become absurd.
What’s fueling this? As they say, it all begins with strike one. Kershaw averages a first-pitch strike to three of every four batters, the highest rate in baseball among starters since at least 2002. What happens when you throw first-pitch strikes? You don’t throw first-pitch balls. A pitcher’s able to get ahead and possibly stay ahead.
The league-average rate of pitches thrown with the pitcher behind in the count is 17 percent. A year ago, Kershaw came in at 15 percent, better than average. This year, he’s at 11 percent. Kershaw’s ahead more than ever.
And when the pitcher is ahead, the hitter has to be on the defensive. What else do we observe? Kershaw’s throwing seven out of every 10 pitches for strikes, one of the highest rates in recent baseball history. It’s not that he’s throwing a ton more pitches in the strike zone; it’s that, behind, hitters have had to swing at more pitches out of the strike zone. A pitcher who works ahead forces hitters to expand, and what we see is that, last year, hitters swung at 33 percent of Kershaw’s pitches out of the zone. This year they’re up to 40 percent. Pitchers love swings at balls, regardless of whether the swing makes contact.
So Kershaw’s gotten ahead more, and that’s great. That’s also not everything. Take a look at Kershaw’s career rates of two-strike pitches that registered strikeouts:
Kershaw hasn’t just been better about staying ahead; he’s also been better about seizing two-strike opportunities. His rate this season is the best of his career by far, and while the reasons might be many, one might notice something from Kershaw’s Brooks Baseball page. PITCHf/x tracks every pitch thrown in the majors, and it’s saying something about his slider.
Specifically, Kershaw’s slider this year has been about two miles per hour faster than it was last year. His fastball velocity hasn’t meaningfully changed. His curveball velocity hasn’t meaningfully changed. His changeup velocity is up, but that’s a rare pitch for him. The slider, for whatever reason, is just rocketing in there, and batters have swung and missed at it 58 percent of the time. Batters used to miss the slider about four of 10 swings. Now it’s closer to six. Of all regular pitches thrown by starting pitchers in 2014, no individual pitch has been more difficult to hit than Kershaw’s slider, which isn’t even his most famous breaking ball.
If you want to try and spot anything, be my guest. Here’s a Kershaw slider from 2013:
Here’s a Kershaw slider from 2014:
One of them was 86 miles per hour. One of them was 90 miles per hour. The slider was already an amazing pitch, but there’s no way it hurts to be able to get it on the plate even quicker. A better slider means a better everything, as a rising pitch-tide lifts all pitch-boats. Batters bracing for the slider have also struggled more against the fastball and curve.
There’s one last thing, and it might be the most significant factor. You wouldn’t think Clayton Kershaw was a guy who needed to change his approach, but change it he has, through at least 2014’s seven starts. As a pitcher who works up and down, Kershaw, before, spent a lot of time higher in the zone, and beyond.
This season, somewhat suddenly, Kershaw has lived down, presumably explaining the considerable hike in groundballs. This chart will tell you what you need to know. One line shows Kershaw’s rate of pitches at least three feet above the ground. The other line shows Kershaw’s rate of pitches two feet or fewer above the ground. The center of the average strike zone is around 2.5 feet above the ground.
There’s something of a steady trend, but then there’s a huge change between 2013 and 2014. A year ago, Kershaw threw 28 percent of his pitches at three feet or higher, and 33 percent of his pitches at two feet or lower. This year, he’s thrown 13 percent of his pitches at three feet or higher, and 42 percent of his pitches at two feet or lower. He’s thrown more low pitches than sinkerballers like C.J. Wilson and Charlie Morton. It’s not like, in the past, Kershaw was getting burned up in the zone, but he’s adjusted anyway, and it’s hard to imagine this is a coincidence.
Let’s try a slightly different approach. Kershaw, mostly, faces right-handed batters. Last season, he threw 33 percent of pitches to righties in the upper third of the zone, or higher. He threw 45 percent of pitches to righties in the bottom third of the zone, or lower. This season, those same numbers are 20 percent and 61 percent.
It’s not just about breaking balls, either; against righties, he’s dropped from 38 percent high fastballs to 26 percent high fastballs. Kershaw’s made a deliberate effort to stay down. He’s never had a home-run problem, but now he’s among the groundballing elites.
One might hazard a guess that Kershaw is trying to keep the ball away from a mediocre defensive outfield. But then, he’s also supported by a mediocre defensive infield, so it’s not like there’s a lot of sense in that. I don’t know why, exactly, Kershaw’s pitching differently, but I’m confident that he is, and though it didn’t seem like he was in need of a change, the best players remain a step ahead of the competition. Players aren’t static. Kershaw isn’t the same as he used to be. Felix Hernandez isn’t the same as he used to be.
Yasiel Puig isn’t the same as he used to be. Kershaw has his reasons for this, and according to his deeper numbers, he’s on pace to have one of the better starting-pitcher seasons in recent decades. He was already being counted on for one of those, but now he’s going about it a little differently.
Clayton Kershaw has been fantastic for years. In the last three seasons, he’s won two Cy Youngs and finished second for another. Now this season, he’s pitching more aggressively and he’s pitching more down, with a faster slider to go with the exact-same fastball. His strikeouts are up, his grounders are up, his swings at pitches out of the zone are up, and his walks are down. His ERA might be up, but that might be the least meaningful number of all. Somehow, Clayton Kershaw might’ve found a way to improve.
At least, he’s found a different way to keep himself a superstar. The Dodgers have their issues, but Kershaw right now couldn’t be less of one.