PHOENIX (AP) – The Arizona Diamondbacks’ .248 batting average is the worst in the National League. They’ve been outscored by 21 runs this season.

And yet, they lead the NL West with nine games left in the regular season.

“Sometimes, I struggle to try to come up with a reason that our record is the way it is right now,” manager Bob Melvin said. “It’s significant contributions from the entire group.”

A stalwart bullpen, led by closer Jose Valverde, has been invaluable. But the Diamondbacks have built the NL’s best record – 86-67 through Thursday – by cobbling together veterans, prospects and callups from the minors.

“I don’t know if I have the right answer,” pitcher Micah Owings said. “I don’t know if there is a right answer.”

Arizona, trying for its first playoff berth since 2002, and opens its final home series of the season Friday night against the Los Angeles Dodgers.

Looking at the stats, the Diamondbacks’ success is a bit mystifying:

• Journeyman reliever Juan Cruz has more wins than Randy Johnson, a future Hall of Famer. Cruz picked up his sixth victory Wednesday night against San Francisco. Johnson won four games before season-ending back surgery.

• Miguel Montero, a part-time catcher, has more homers (10) than third baseman Chad Tracy, who had seven when surgery finished his season.

• No one will drive in 100 runs or win 20 games.

• The Diamondbacks have used five leadoff men and eight cleanup hitters.

“It’s a different person every night,” said All-Star second baseman Orlando Hudson, who had season-ending thumb surgery Monday. “That’s all I can say to that. That’s it. Rookies, veterans, everybody helps out.”

Infielder Mark Reynolds began the season at Double-A Mobile, then hit .426 with four homers and 15 RBIs in 15 games for the Diamondbacks in May.

Catcher Chris Snyder, hitting .219 at the All-Star break, had eight straight hits with runners in scoring position during one stretch.

Outfielder Jeff Salazar, claimed off waivers from Colorado during spring training, leaped at the right-field wall to rob San Diego’s Brian Giles of a homer July 13. It was Salazar’s fourth start after being promoted from Triple-A Tucson.

Right-hander Edgar Gonzalez has gone 8-2 in 10 starts and 20 relief appearances.

“I think they’re a great story,” San Francisco manager Bruce Bochy said. “I think they’re the story of baseball, the surprise team in our sport this year.”

From July 26-28, the Diamondbacks won three straight games in the last of the ninth. Their 32 one-run victories are the most in the majors and a franchise record.

The Diamondbacks have twice matched the team record for the greatest deficit overcome to win, overcoming six-run gaps to beat Pittsburgh 9-8 on May 19 and to defeat Tampa Bay 10-8 on June 19.

On Sept. 8, the Diamondbacks gave up seven runs in the third inning as they fell behind St. Louis 7-3, then rallied for a 9-8 victory.

“I think there’s a lot of fight in this team,” Melvin said. “One of the things we do pretty hard is we fight hard all the time throughout the game, and we have to.”

Conor Jackson said the Diamondbacks have a belief that they’re never out of a game, and that someone will come up with a big hit almost every night.

“That whole batting average stat doesn’t really mean anything,” Jackson said. “It’s all about the ‘W.’ “

True enough. Two years ago, San Diego was outscored by 42 runs and still won the NL West, albeit with an 82-80 record.

“We get down, we come back. We’re ahead, and we keep it,” Jackson said. “We get those big hits in big situations.”