Kershaw, however, is headed for a softer twilight — older and less dominant than Koufax, forced to flourish in more subtle ways.

“Clayton is probably more like Andy Pettitte than Sandy at this point in his career,” Dodgers Manager Dave Roberts said. “In a big spot, he always manages to make a big pitch to get out of trouble, just like Andy did. He somehow finds a way.”

As the Dodgers begin their postseason as the National League’s best team, they’re counting on Kershaw — again — to end a championship drought that has stretched to 31 years. . Kershaw, who ranks among the N.L.’s top-10 pitchers in wins, E.R.A., WHIP and opponents’ batting average, has continued to succeed despite a decidedly less-threatening fastball than that of Koufax, who was estimated to throw in the high 90s. According to Fangraphs, Kershaw’s four-seam velocity has declined every year since 2015 and now sits at a modest 90.4 miles per hour.

When asked if there was a way to regain his old sizzle, Kershaw, 31, grinned and said, “I sure hope so.” But the effects of age seem to be emerging: He has been on the injured list numerous times for lower back and shoulder issues, prompting the Dodgers to ease up on his workout routines between starts.

The results have been encouraging. Kershaw said he has been pain-free for months, and he hasn’t missed a start since April 15. He has neutralized hitters by changing their eye level from pitch to pitch , adding and subtracting velocity throughout the at-bat to upset their timing. In his final regular season start a week ago, he threw a gem against the San Diego Padres: striking out seven in six innings with just two hits allowed.

Roberts said, “it’s what pitchers do over time to remain successful — they become smarter. Clayton doesn’t throw as hard as he used to, but he’s made the necessary adjustments. Some pitchers can’t; they’re the ones who end up with shorter careers. But the ones who last are the ones who evolve.”