No one knows the value of home runs like Mr. October.

Keeping up their amazing home run barrage is the best way for the Yankees to win their first World Series title since 2009, according to Reggie Jackson, who believes in his baseball soul the road to a championship must include home runs to support a pitching staff.

“You can win the World Series with homers,’’ Jackson told The Post. “There is no way anyone is going to convince me or I am going to sell out and say, ‘You don’t need home runs to win.’ I’m out. You’re talking to the wrong guy.’’

Mr. October is the right guy when it comes to understanding how to win in the postseason.

The Yankees begin a three-game showdown series against the A’s on Friday night at Yankee Stadium, a week after the A’s swept the Yankees in Oakland.

Jackson, who is tied for fifth place all time with 10 World Series home runs — eight with the Yankees and two with the A’s — knows the value of those home runs and the importance of the record-setting month the Yankees have had, bashing 70 home runs with two more games in August. That has shattered the major league mark for home runs in a month and given them 250 for the season, which trails only the Twins at 258.

One of their goals is to surpass the Twins and break their own major league record from a year ago when they clobbered 267 home runs. The Yankees have at least 20 home runs from all nine spots in the lineup, with Gleyber Torres leading the Yankees with 33 home runs.

Jackson has a major backer in Aaron Judge, who is on a home run tear, having hit five home runs the last six games. In that six-game span the Yankees have hit 18 home runs.

Home runs work any time of year, but in the postseason they can be especially effective, Judge said.

“It’s huge,’’ he said. “A game can swing just like that in October with home runs.

“You know, you can get on base, single, single. But if you have a team that can not only get on base, but also when those guys get on base and now there is a three-run home run,’’ Judge said, snapping his fingers for effect, “now you are up three. It just changes the whole dynamic of the game, especially in the postseason with how important every single pitch is, that makes the other team worry about it.

“When you know one through nine can hit a home run and give you a great at-bat, it changes the whole game. And that is what we do, that’s the key to our success.

“We’re dangerous. That’s the bottom line.’’

That is the bottom line. It’s in the Bronx Bombers’ DNA.

“All you have to do is point to the Yankees, Ruth and Yogi and Mickey, myself, I think four or five of the top six or seven World Series home run hitters are Yankees,’’ Jackson said.

Reggie knows his home run history.

Mickey Mantle leads the way with 18 World Series home runs, followed by Babe Ruth at 15, Yogi Berra at 12, then Duke Snider (11). Lou Gehrig and Reggie both have 10, while Joe DiMaggio, Frank Robinson and Bill Skowron have eight each.

The Yankees have had more opportunity, of course. They own 27 world championships, but to get No. 28, Judge & Co. are going to have to hit the long ball to support the Yankees pitchers.

“You’ve got to have good pitching. But the World Series is homers,’’ Jackson said.

Each of the last three World Series winners out-homered their opponents.

Reggie also pointed to the Dodgers’ long-ball success. The Dodgers are third in home runs with 231 and are favorites to make it back to the World Series for the third straight year.

Even the great pitchers make mistakes, Reggie said.

“It doesn’t take much if you are facing guys who can hit,’’ Jackson said.

The Yankees can hit.