ST. LOUIS -- No team in baseball has better maximized its young talent this year than the Cardinals, who have employed a Major League-most 20 rookies in a season that won't end until sometime in October.
These haven't been mere placeholders, auditioning for a place on the roster next season. Rather, they are a critical reason why the Cardinals sit on the precipice of capturing their first division title since 2009, needing only one more win -- or one Pirates loss -- to take that crown.
A day after rookie Michael Wacha tossed 8 2/3 no-hit innings, five rookie pitchers combined to hold the Nationals scoreless for the final eight innings on Wednesday. Shelby Miller built the momentum, pitching the Cardinals to a 4-1, series-sweeping win over the Nationals in front of 40,597 at Busch Stadium.
The victory, coupled with Cincinnati's shutout loss, eliminated the Reds from contention in the National League Central. Pittsburgh lost later in the afternoon, too, thereby shredding the Cardinals' magic number to one. The Cardinals can now finish in no worse than a first-place division tie.
The Cardinals also moved a half-game up on the Braves, who fell to the Brewers, 4-0, for home-field advantage.
"Guilty again," manager Mike Matheny said, when asked if he peeked at the scoreboard in-game. There were audible cheers coming from the clubhouse, too, when the Cubs jumped in front of the Pirates on a sixth-inning home run by Darnell McDonald.
"I think there's definitely some excitement," said Trevor Rosenthal, who saved all three games in the series. "We're playing well right now, and that always gives us good energy."
Thirty-six of the Cardinals' 94 wins this season have been secured by rookie pitchers. Miller owns 15 of them, more than any other rookie in baseball. He joins Adam Wainwright and Chris Carpenter as the only pitchers to win at least 10 games at Busch Stadium III in one season.
In his final regular-season start, the 22-year-old right-hander showed the Nationals just how much he has evolved since he faced them twice during Spring Training and again in April. Pulling back from his reliance on the high fastball and mixing his pitches in order to compensate for less-than-ideal crispness, Miller was able to rebound from a laborious 27-pitch first inning.
A leadoff walk stung him in that opening frame. After he closed it, Miller did not allow another a runner to reach scoring position. He covered his last five innings with 63 pitches.
"I know efficiency has been a big thing for me lately," Miller said. "I'm just trying to get deep into the games to help the bullpen. Just being more of a starting pitcher -- mixing it up, locating pitches and doing a better job of getting hitters out quickly."
In the bigger picture, Miller's quality start was more of the same from the Cardinals' rejuvenated rotation. After trudging through August with a 4.30 ERA, the starters have a 2.60 ERA in 24 September games. The group has 15 quality starts.
The Cardinals' offense erased that Washington lead in the third, when Daniel Descalso doubled and scored on Matt Carpenter's groundout. Yadier Molina's two-run single in the fourth put St. Louis in front. That lead was then padded with a solo homer from rookie Matt Adams, who is batting .338 with eight home runs since Allen Craig went down injured.
"I think it starts out when we get in the system, knowing the Cardinal Way," Adams said. "When you come into the Minor Leagues, you're expected to win. It's the same here."
Then there is the bullpen, saturated with young talent. Three of the four Cardinals relievers to pitch on Wednesday made their Major League debut this year. The other (Rosenthal) is 23 years old and still maintains rookie status.
Seth Maness entered in the seventh and induced a double play to erase Miller's leadoff walk.
"It's not something I'm trying to do," Maness said. "I'm just trying to come in and hit a spot. [I] can't control where it goes after it leaves my hand."
Intentional or not, Maness has become the go-to double-play guy. He leads all NL relievers with 15.
"He's like a robot out there pitching," Miller said. "I told him he's going to have to show me that pitch next year in Spring Training because I'm going to need it to get some quicker outs."
Matheny lined up Kevin Siegrist -- who extended his scoreless appearance streak to 26 -- and Carlos Martinez -- who retired Ryan Zimmerman and Jayson Werth for the second time in this series -- to pitch the eighth. Rosenthal, though he hasn't been given the title, took the closer duties for a third straight day.
The bullpen pitched 5 1/3 scoreless innings in this series. Five of those innings were covered by rookies.
"They have good starters, but I think what sets them apart is their bullpen," Werth said. "Even last year in the playoffs, when you look at Game 5 [of the NL Division Series], for example, we chased the starter and for five or six innings, they bring in guys that throw 96-plus [mph]. The bullpen is good. They have a lot of velocity and they have a lot of depth."
"You give them opportunities and you just can't help deny the talent," Matheny said. "We saw some young guys with really good talent, and they're letting it shine."
The Cardinals won all six of their games against the Nationals this season, marking just the third time in history that the Cardinals went 6-0 or better against one team.
"I'll tell you: They kicked our butt in just about every aspect of the game," said Washington manager Davey Johnson. "I tip my hat to them. Matheny has done a good over there, I wish them luck. They had their way with us."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.