Dodgers are pitching themselves into the playoffs, but what then?

Pitching wins. Especially in the playoffs.

That’s one of those baseball adages, like the infield fly rule, that everyone simply accepts but no one has really proved.

“There’s no question pitching’s at a premium because every team in the postseason has a stud at the top of their rotation, and a two and a three and a four that are very good. It’s just a common theme because you can’t really get there without it,” says Dodgers President Stan Kasten.

“Pitching is king,” agrees General Manager Ned Colletti. “If you don’t have pitching, you’re going to need so much offense and such a great defense, that you’re going to find yourself chasing the scoreboard on a lot of days.”

Kasten and Colletti should feel pretty good then, right? Because with Sunday’s 2-1 win over the San Diego Padres, their Dodgers are virtually assured a playoff berth, leading the National League West by 111/2 games with 26 games to play.

And with Zack Greinke holding the San Diego Padres to one run and two hits through seven innings, the Dodgers’ staff earned-run average since the All-Star Game is down to a microscopic 2.19, more than half a run better than any other team in baseball.

The staff’s top four starters — Greinke, Clayton Kershaw, Hyun-Jin Ryu and Ricky Nolasco — are a combined 22-5 with a 1.91 ERA in the second half. And the bullpen, which contributed two scoreless innings Sunday, is holding opponents to a .190 batting average since mid-July. No other team is even close.

So if the Dodgers are going to the playoffs, and if pitching wins in the playoffs, why not just give the Dodgers the World Series trophy now and we can all spend October watching football?

Well, because in addition to “pitching wins,” there’s one other adage Kasten subscribes to.

“The postseason,” he says “is a crapshoot.”

Nobody knows that better than Kasten, who ran the Braves during a stretch in which Atlanta led the majors in ERA seven times in eight seasons, yet had one National League pennant and no World Series rings to show for it.

Still, the Dodgers will take their cue from their president and base their October hopes on pitching anyway — although some of them are keeping their fingers crossed just the same.

“Obviously our pitching is really what this thing’s been built on,” Manager Don Mattingly says. “I know we’ve got a lot of big-name guys through the lineup, but pitching is really what does it. It’s not quite as glamorous as home runs and all the other stuff. But those guys, day in and day out, give you a chance to win.

“You get a chance to win 2-1 and 3-2 and 1-0. So pitching really is what’s going to take us forward.”

It’s also what’s taking the Braves, Pirates, Reds and Cardinals — the NL’s other likely playoff teams — forward. Because pitching not only wins in the playoffs, it gets you there as well. Which is why it’s no surprise those teams, along with the Dodgers, have the league’s top five pitching staffs. Their rotations are the league’s five best as well.

Still, the Dodgers may might be just a cut above the best.

“Their starting pitching is outstanding,” says San Diego Manager Bud Black, a former big-league pitcher and pitching coach. “You’ve got to be able to pitch with Kershaw, you’ve got to pitch with Greinke, you’ve got to pitch with Ryu. You’ve got to pitch with their bullpen.

“In the playoffs, you have talented people. That’s why they’re in the playoffs.”

What October really comes down to then isn’t just pitching. Or hitting or fielding or baserunning. Kasten learned that much in Atlanta.

It’s a crapshoot, remember?

“When you get into the playoffs, there’s no guarantees,” Black says. “All series come down to … a big pitch here or there. And it’s not easy to win. It’s not.

“The teams that win, things go their way.”

But it all starts with pitching.

kevin.baxter@latimes.com

Twitter: @kbaxter11