Thanks to this pitch, Kershaw is still elite

April 18th, 2022

With all of the controversy surrounding Dodgers manager Dave Roberts' decision to pull Clayton Kershaw from his season debut after seven perfect innings against the Twins, the particulars of his performance seemed to fall by the wayside.

There was Kershaw, with the gray starting to become more prominent in his beard, retiring all 21 batters he faced in the first start of his age-34 season after his 2021 campaign was cut short by an elbow injury. Not only that, but he also struck out 13, and he did it with a four-seam fastball that averaged just 89.9 mph.

Yes, you read that right -- 89.9 mph.

It was only the 11th time in 414 career games (postseason included) that Kershaw, who is set to start against the defending World Series-champion Braves on Monday, posted an average velocity below 90 mph with his four-seamer. And yet, the Twins couldn’t touch him.

Kershaw’s slider took on a starring role in the effort, as he collected 11 of his 13 K’s with the pitch -- the most in any start during his career. Minnesota hitters went 0-for-16 overall against his slider, which he threw more than half the time.

In a way, the start was a microcosm of how he has evolved as a pitcher, combating reduced velocity by simply throwing his heater less and his slider more.

Here’s a closer look at why, in his 15th big league season, Kershaw can still be an elite starter for the Dodgers, who brought him back on a one-year, $17 million deal in March.

What’s the same

To be clear, Kershaw’s evolution hasn’t been a complete reinvention. He hasn’t introduced a 60 mph eephus a la Zack Greinke, or worked on a changeup to make his repertoire more diverse.

The left-hander was a four-seamer/slider/curveball pitcher when he won three Cy Youngs and an MVP Award in a four-year span from 2011-14, and he remains a four-seamer/slider/curveball pitcher. Even when he threw harder earlier in his career, he wasn't someone who needed to rely on top-of-the-scale velocity to succeed, perhaps making this an easier transition for him.

While his velocity has dropped, Kershaw hasn’t had to become a pitch-to-contact guy. His strikeout rate across 2014-20 was 29.7%. Last season, it was 29.5%.

Of course, that doesn’t mean he is shying away from contact. His zone rate was still above the MLB average last season, and he walked only 21 of the 488 batters (4.3%) he faced despite posting the highest slider usage rate of his career. His walk rate from 2014-20? An identical 4.3%.

While Kershaw’s walk rate is certainly aided by his penchant for getting batters to chase, he hasn’t lost his ability to miss bats on swings in the zone, either. And though attacking hitters has left him more prone to allowing homers as his velocity has decreased, his low walk rate tends to mitigate the damage. Of the 23 homers he allowed across 2020-21, 17 were solo shots.

We haven’t portrayed Kershaw’s fastball in the best light so far, but the pitch remains tough for batters to square up when they make contact. In 2021, the hard-hit and barrel rates against his four-seamer were among the lowest in the game, likely because he can still locate the pitch so well.

Kershaw frequently targets the glove side of the strike zone (away to left-handed batters, inside to righties) with both his four-seamer and slider, using them in tandem to keep hitters off balance. As you can see in this 2020 clip from Pitching Ninja, doing so makes it incredibly tough for batters to decipher what pitch is coming. The two pitches travel to the plate on a nearly identical plane.

What’s different

The slider has become Kershaw’s go-to pitch. Last season was the first time in his career his most-used offering wasn’t his four-seamer, as he threw his slider a career-high 47.6% of the time, compared to 36.7% for his fastball. The disparity was even larger in his first start of 2022.

With Kershaw continuing to mix in his curveball as well, he threw a breaking ball more often than any other starting pitcher in the Majors in 2021.

It coincided with the highest whiff rate (misses/swings) he’s had in any season under Statcast tracking (since 2015), putting him in the same bat-missing neighborhood as some of baseball’s most dominant starting pitchers.

Highest whiff rate, SP, 2021
Minimum 500 swings against
Jacob deGrom: 41.4%
Tyler Glasnow: 37.0%
Corbin Burnes: 36.5%
Shane Bieber: 36.4%
Clayton Kershaw: 34.6%
Dylan Cease: 34.6%
Max Scherzer: 34.2%
Patrick Sandoval: 33.9%
Freddy Peralta: 33.6%
Carlos Rodón: 33.2%

That marked a 7.0% increase from his 2020 whiff rate, tied for the 10th-largest jump among qualifying hurlers.

Kershaw’s increased reliance on his slider has become especially noticeable in two-strike counts. When he was younger, his four-seamer saw much more action in these situations. However, he went to the four-seamer on only 18.3% of his two-strike pitches in 2021, and against the Twins last week, he threw it just twice on 26 two-strike pitches.

Bumping up his slider usage has enabled Kershaw to put hitters away more quickly once he gets to two strikes, not only helping him avoid those pesky two-strike hits but also allowing him to preserve his 34-year-old arm.

Kershaw racked up 108 strikeouts with his slider in 2021, making it one of 12 individual pitches across the Majors that were responsible for 100-plus K's. He managed that in just 121 2/3 innings, the fewest by far among the pitchers on the list.

Overall, his 29.3% putaway rate -- the percentage of two-strike pitches that result in a strikeout -- was the highest of his career. Only deGrom and Burnes fared better in this department among starting pitchers who recorded at least 50 K’s.

Highest putaway rate, SP, 2021
Min. 50 strikeouts as a SP
Jacob deGrom: 38.7%
Corbin Burnes: 29.9%
Clayton Kershaw: 29.3%
Tyler Glasnow: 29.2%
Shane Bieber: 27.9%

Due in part to his injury issues, the conversation about the top starting pitchers in baseball no longer seems to include Kershaw, who has ceded the No. 1 starter spot on the Dodgers to Walker Buehler. It remains to be seen if he can avoid the injured list in 2022. He hasn’t made 30 starts in a single year since 2015, dealing with a myriad of back and arm problems over the past six seasons, and pitchers don't tend to get more durable with age.

But the veteran has shown that, when healthy, his status as an ace shouldn't be in question, even with a fastball that would be considered a below-average changeup for some of his peers.