The Post Sports Live crew debates where Matt Williams should play Ryan Zimmerman when he returns from the DL to a likely first-place team in the middle of a pennant chase. (Post Sports Live/The Washington Post)

The Post Sports Live crew debates where Matt Williams should play Ryan Zimmerman when he returns from the DL to a likely first-place team in the middle of a pennant chase. (Post Sports Live/The Washington Post)

The Nationals are a World Series team.

That doesn’t mean they will be in the Series this year. Every September there are more “Series teams” than spots available. But for the first time, they play and feel like a team that belongs on such a stage.

For the past three years, I’ve maintained my doubts about the Nats. Contenders, yes. Building into something very special but missing key elements or maturity — yes, that, too. They were talented, entertaining, frustrating and often over-predicted, usually by those who didn’t see them consistently.

Could they get hot at the right time and win a pennant? Such things happen. Would they? Probably not. Even this year, until recently, I’ve seen them as fun but unfinished, still a year away. Not anymore.

For three months, all kinds of factors have fallen into place that usually accompany one of “those seasons.” The Nats have gotten healthy; tightened their defense; incorporated the more efficient base running and situational hitting demanded by their new manager; bonded with the usual goofy home run, walk-off and postgame rituals; and, by damn, sure look like a team peaking at the proper time.

The Post Sports Live crew debates what the odds are that the division-leading Baltimore Orioles and Washington Nationals meet in the World Series. (Post Sports Live/The Washington Post)

After early injuries to key players, the Nats have gone 54-32 since late May, a span of more than half a season in which they’ve played at a 102-win pace. In that time, the only NL team not embarrassed by comparison is the Dodgers, who have won 49 but have less than half of the Nats’ huge 108-run margin of victory. In the AL, the Angels are also 54-32. The Orioles, rumble of thunder, have won one more. As for the A’s, a spring juggernaut, it looks like they’ve returned to earth as just a very nice team.

During a baseball season, the truth is like a coin that constantly flips in the air but hasn’t landed. Both “heads” and “tails” are still possible. The barriers to a pennant are as clear as a Clayton Kershaw curveball or a glance at standings that show the Cardinals, mundane for months and outscored for the year, inexorably grinding down the NL Central as they try to make it back to the Series again this season.

But the validity of the Nats’ case is now clear. Having eight top players sent to the disabled list didn’t derail but merely steeled them. Recently, they have been MLB’s hottest team during a period in which their best RBI man and core personality, Ryan Zimmerman, is back on the DL. Early problems with the Braves (1-7) shifted toward equilibrium (3-2 in their past five meetings). Next week, they collide at Nationals Park.

Excuse the Braves if they’re dizzy. Since they last met, the Nats ripped off a 12-1 streak, then recovered from a hiccup of a sweep in Philadelphia by winning road series against two very strong teams. In Seattle, they hit 10 homers in three days and thumped King Felix Hernandez. In L.A. they answered a loss to Kershaw with a 14-inning, nine-reliever, 26-man win Wednesday that had “this is their year” stamped all over it. Questions got answered, too. In his past 22 games, Bryce Harper has hit .329 with seven homers and a .968 OPS.

Seasons and teams evolve. There’s no inevitability in baseball, only process and, with luck, growth. The Nats show it in every part of their game. At the most macro level, they lead the NL in both ERA and (excluding the goofy mile-high Rockies) scoring, too. At the micro level, they dazzle, succeeding on 84 of 99 stolen-base attempts as well as the best percentage of throwing out opposing thieves and a catching corps that has allowed the fewest wild pitches and passed balls of any team. No pitching staff walks so few. Their star rotation and weakness-free lineup does the big stuff, but they finally master details and keep focus, too.

So if you don’t think this is a World Series team, you’re a few beats behind the music. Not a “going to the Series” team — no one knows that — but one that would look perfectly at home there.

Someone just whispered “Rafael Soriano.” Let me whisper back: Santiago Casilla, Jose Valverde (3.78 ERA), Fernando Salas, Brad Lidge (7.21), Troy Percival (4.53), Brian Fuentes, Jason Isringhausen (3.55), Todd Jones (3.94), Dustin Hermanson, Braden Looper (3.68), Keith Foulke and Byung-Hyun Kim. Common thread: They were all season save leaders on pennant winners since ’01 (lame ERAs included).

As applies to every team, every day, everywhere, injuries can change all this. The Angels recently lost star starter Garrett Richards when he covered first base and his knee collapsed. The Nats’ disguised break was that, though they lost as many or more games to injury as any current contender (and two or three times as many as most), they have lost nobody for the year.

The master puppeteer behind the whole project is General Manager Mike Rizzo. His trades for Doug Fister and Denard Span now look tremendous. His rookie manager, Matt Williams, used 26 players in one game — not one of them incorrectly. At the trade deadline, Rizzo dealt for Asdrubal Cabrera, then picked up lefty Matt Thornton (12 games, 0.00 ERA) for used dental floss. That pair may help the Nats as much as any team’s gaudier, costlier deals.

In contrast, the A’s traded their cleanup hitter for a southpaw and immediately collapsed; their odds to win the AL West are down to 14.2 percent according to FanGraphs.com. Detroit traded for the other flashy pitching prize and did a fast fade. Now the A’s and Tigers might meet in a wild-card game. Jon Lester vs. David Price? Irony?

Las Vegas, no sentiment allowed, has the Nats at 5-2 to win the pennant, behind the Dodgers, and 6-1 to win the Series, behind both L.A. teams and just ahead of the Orioles. As always, there are more “World Series teams” than there are seats at the banquet. But those four clubs, at the least, have Series auras now.

No one knows what will transpire in October. But six-month seasons identify the truly powerful, fully formed teams. Piece by piece, month by month, the Nats have become what they dreamed of being — the real polished article rather than those earlier rough-edged versions.

How far will that take them? Well, to South Capitol Street to start a homestand Friday night, that much is for sure. Then next week begins with a little appointment with the Braves.

Don’t wish these days away. One at a time will do just fine, thanks.

For more by Thomas Boswell, visit washingtonpost.com/boswell.