The velocity on Clayton Kershaw’s slider was down. That’s a good thing

The most memorable slider thrown by Clayton Kershaw on Monday resembled many he threw in the summer and the fall of 2018. The velocity of the pitch registered at 87.6 mph on the Dodger Stadium radar gun as it lazed over the inner half of the plate. The exit velocity hit 102.7 mph as former Dodger Yasiel Puig cranked a two-run, first-inning homer for the Cincinnati Reds.

“I wish I could have done anything,” Kershaw said, “but give up a homer to Puig in that first at-bat.”

That slider will be replayed in the highlight reel assembled for Puig’s career. But for Kershaw and the Dodgers, the more meaningful sliders, the ones which will resonate for the team beyond Monday’s 4-3 victory, came as the game progressed. For in his first start of 2019, Kershaw demonstrated an ability to generate the teeth the pitch had been missing last year.

Kershaw did not yield another run after Puig went deep. He finished the evening with five hits allowed, six strikeouts and zero walks. He produced 14 swinging strikes; seven came after sliders. He lasted seven innings, one more than manager Dave Roberts expected.

As Kershaw traverses the second decade of his career, the speed of his fastball invites scrutiny. The pitch averaged 90 mph on Monday, never exceeding 91.2 mph. He sat in the same range last season, a significant drop from the 93-mph heater he produced as recently as 2017.

The aging curve invites simple math. The older you get, the slower your fastball. Kershaw is living this truism. But different logic applies to his slider. Velocity does not guarantee success.

After dealing with shoulder and back issues in the first half of 2018, Kershaw struggled to generate depth on his slider. The pitch became something closer to a cutter. On Monday, in his first big-league action after two minor-league rehab starts, Kershaw spun sliders at 86.8 mph, down from the 88-89 mph offering from last season.

“His slider is obviously a special pitch,” catcher Austin Barnes said. “He has a good mix. He has the ability to put his fastball where he wants. But his slider is pretty unique. When he has that pitch going, it’s tough on hitters.”

The fastball always draws attention. The curveball is Kershaw’s most famous pitch. But the slider is his most important. On a night when he made 84 pitches, he threw 39 sliders, using a breaking ball as his primary weapon. He demonstrated a blueprint for success moving forward.

“I thought the curveball was really good tonight,” Roberts said. “I thought the slider got better as the game went on. He mixed in and out very well tonight. A lot of efficiency. There was some soft contact.”

The homer by Puig did not rattle Kershaw. He retired the next nine batters he faced, aided by Reds pitcher Luis Castillo misreading a bloop into right field and getting thrown out at first. Kershaw flooded the bottom of the zone and produced groundouts.

In the sixth, Kershaw resembled the pitcher he was before suffering a slew of back injuries. He dusted reliever Michael Lorenzen on three pitches. He froze catcher Curt Casali with an 86-mph slider on the outside corner. He fanned third baseman Eugenio Suarez with an 87-mph slider on the inner half. The pitch bit and snapped, darting downward rather than cutting.

“He knows how to pitch, he knows how to hit spots,” former Dodger Matt Kemp said. “He’s been doing it for a long time. I’m sure he’ll figure out what he has to do to be successful this year.”

After Kershaw signed his three-year, $93-million extension in November, he vowed to use the winter to reclaim some of the ability he felt he had lost over the past few seasons. The obvious wonder was whether he could produce the fastball of his youth. On Monday, he showed why it might be just as beneficial to spin the slider of his mid-20s.

“They were sporadic; some of them were good, some of them weren’t,” Kershaw said. “For me, I think it was a success overall. Got some swings and misses. Got some behind-in-the-count easy outs, things like that. That was what I need.”

Sign up for our daily sports newsletter »

andy.mccullough@latimes.com

Twitter: @McCulloughTimes