Years from now, Charley Steiner said, when he recalls one of the greatest pitching performances in major league history, he will first remember Clayton Kershaw the hitter. In the bottom of the eighth inning Wednesday night, when he came to bat with an eight-run lead, Kershaw, the ace of the Los Angeles Dodgers, competed with everything he had.

“He grounds routinely to the shortstop, and he’s sprinting every step of the way to the bag,” Steiner said Thursday. “And I’m thinking, ‘Who on earth could possibly be wired in such a way?’ He’s three outs and one error away from a perfect game, and there is no governor on his engine.”

Kershaw finished off the Colorado Rockies in the ninth, retiring Corey Dickerson with a vicious slider for his 15th strikeout. It was not a perfect game because of a throwing error by shortstop Hanley Ramirez in the seventh. But it was one of a kind: the first time in major league history that a pitcher struck out at least 15 without allowing a hit or a walk.

It was the second no-hitter of the major league season and the second by a Dodger: Josh Beckett stymied the Philadelphia Phillies on the road last month. Kershaw and Beckett are the first teammates to throw complete-game no-hitters in the same season since Burt Hooton and Milt Pappas of the 1972 Chicago Cubs.

But there are no-hitters and there are games for the ages — and Kershaw’s ranks among the greatest singular performances in history. His effort computed to a game score of 102, ranking second only to Kerry Wood’s 20-strikeout one-hitter for the Cubs in 1998, which registered 105.

Game score, developed by Bill James, follows this formula: start with 50 points; add 1 point for each out, 2 for each completed inning after the fourth and 1 for each strikeout; subtract 1 point for each walk, 2 for each hit, 2 for each unearned run and 4 for each earned run.

Three games scored 101 —Matt Cain’s perfect game in 2012, Nolan Ryan’s no-hitter in 1991 and Sandy Koufax’s perfect game in 1965. Six scored 100 — Randy Johnson’s perfect game in 2004; no-hitters by Ryan in 1973 and Warren Spahn in 1960; and shutouts by Brandon Morrow (2010), Curt Schilling (2002) and Ryan (1972).

The metric does not quantify degree of difficulty or circumstance. Thus, baseball’s two postseason no-hitters — Don Larsen’s perfect game in the 1956 World Series and Roy Halladay’s no-hitter in the 2010 playoffs — score only a 94, ranking below 133 regular-season efforts and two others in the postseason, by Roger Clemens and Tim Lincecum.

Kershaw, who won, 8-0, faced a Rockies lineup that was missing the injured Nolan Arenado, Michael Cuddyer and Carlos Gonzalez. Koufax recorded one fewer strikeout in his perfect game than Kershaw did Wednesday, but he faced three future Hall of Famers — Ernie Banks, Ron Santo and Billy Williams — and the final score was 1-0.

Then again, Koufax was conditioned to throw nine innings. The perfect game was his 23rd complete game of 1965; Kershaw’s no-hitter was the 13th complete game of his seven-year career.

Ranking greatness makes for good debate, but ultimately it is futile. While it was certainly the best game for Kershaw, a two-time Cy Young Award winner, it was not too far from his norm. It was the fifth time this season that Kershaw has struck out at least nine without allowing a walk.

“The thing about Kershaw is that almost every start, he’s capable of doing this,” Steiner said. “So it wasn’t like, ‘Oooh, he’s bringing something special tonight.’ Because every night he pitches, he’s bringing something special.”