PHOENIX -- The kids have made it this far. Now the pressure rises.

The young Arizona Diamondbacks, with their rallying cry "Anybody, Anytime," head into the division series against the Chicago Cubs with the best record in the National League.

This unlikely mix of rookies, role players and a few veteran leaders finished last in hitting and were outscored by opponents overall.

Yet by winning the close ones, with solid pitching and timely hits from just about everyone at one time or another, Arizona advanced to the postseason for the fourth time in the franchise's 10-year history.

"In this day and age, I've never seen a team like this," said left fielder Eric Byrnes, a high-energy leader of the team. "This is a group of unselfish guys. They think team first and not as a bunch of individuals. That's rare today in sports."

This Arizona team is a far cry from the other three that made the playoffs. Those were big-name squads that came to the Diamondbacks for big money, some of which is still on the books. The 2001 World Series champions featured Randy Johnson and Curt Schilling in their prime.

These Diamondbacks are homegrown, mostly the product of what was considered one of the best farm systems in the majors. It seems a classic case of the whole being greater than the sum of its parts.

"The key is this team plays well together," said manager Bob Melvin, who was Arizona's bench coach from 2000 to 2002. "When you win 32 one-run games, you have to. Our bullpen has contributed to those kinds of wins. And we did hit 12 pinch-hit home runs."

Conventional wisdom had the Diamondbacks a year or two away from contention. That opinion seemed justified when Arizona lost eight of 10 going in to the All-Star break.

The turning point, rookie center fielder Chris Young said, came July 19 at Wrigley Field against the Cubs after the Diamondbacks had lost three of four in Milwaukee.

"We'd looked bad in Milwaukee and got together as a team the evening before the start of the Chicago series," rookie center fielder Chris Young said. "We were at a point where the season could go either way for us. It went the right way. We had to find a way to turn it back uphill, and we did that starting against the Cubs."

Arizona lost the opener then took the next two from Chicago. That began an eight game winning streak. From July 21 to Aug. 11, the Diamondbacks were 21-5.

Tony Clark was the acknowledged leader in the clubhouse, talking to the young players and giving the place a professional presence. He also split time with Conor Jackson down the stretch.

Three Diamondbacks made the All-Star team -- second baseman Orlando Hudson, ace starter Brandon Webb and closer Jose Valverde. But the Diamondbacks really had no stars, especially at the plate.

"We haven't had that one big guy in our lineup that is dominating and winning every ball game," Young said. "We have eight guys that can win a game for us -- literally every single starter. I'd say everybody on this team has won a game for us."

He's not exaggerating. When Jeff Salazar hit a ninth-inning, pinch-hit home run -- his first homer in nearly a year -- to beat the Giants in San Francisco on Sept. 10, it was apparent that something special was going on.

Along the way, the Diamondbacks lost Johnson, Chad Tracy and Hudson to season-ending injuries.

Melvin would mix and match lineups and the results were usually good.

A few Diamondbacks can hit it deep. Young had 32 home runs, nine of them to lead off a game. Byrnes hit 21. Mark Reynolds, brought up from Double-A Mobile when Tracy got hurt, hit 17 homers, as did Clark.

But this is a team that relies on speed. Byrnes stole 50 bases, Young 27.

"We run and run often and will run into the playoffs," Byrnes said. "We will do everything we can to create runs because we can't sit back and wait for the three-run homer. There are no perennial 40 home run guys here."

Veterans Young and Jeff Cirillo have taught the youngsters to cherish the experience.

"I spoke with Jeff Cirillo. He's played 15 or 16 years and 1,600 games and never been to the playoffs," Young said. "And Tony Clark told me to appreciate this moment of getting to the playoffs as a rookie. They both stressed that it isn't easy to do and not to take it for granted. I won't take it for granted."

The Diamondbacks haven't gotten all that much national attention for their unusual route to the playoffs. That should change when the ever-popular Cubs come to town for the first two games of the series Wednesday and Thursday nights.

"Any time you play the Cubs, it can be a traveling circus," Melvin said. "There is a lot of excitement."

AP sports writers Pat Graham and Arnie Stapleton in Denver contributed to this story.