The amused expression on Nationals Manager Davey Johnson’s face and the composure, with only the slightest smile, on the mug of owner Ted Lerner told the whole bizarre bifurcated story of their team’s playoff-clinching celebration on Thursday night.

Washington is back-slapping delighted, and should be, that it has a baseball team in the postseason for the first time since 1933. But, ironically, the town also has almost no sense yet of how exceptional that team already is. The Nats themselves do. The disconnect on Thursday was almost total between 30,359 fans cheering for “Nats Clinch” and the team itself which, in Johnson’s first words, thought, “What’s the big deal?”

Almost no one has more right to ordain a celebration for the Nats than Lerner, who’ll be 87 next month and knew the ’33 Nats lineup by heart when they played in the World Series. “It’s only a first step,” he said, muting congratulations as he accepted them.

In an odd sight, Nats players were given champagne in a town that’s had no reason to pop any in 79 years, yet they didn’t spray it, just clinked and toasted a tad. If anything, they blended graciousness, a sense of the almost infinite patience of some of their fans, with a self-confident edge. “I have a much bigger picture in my mind,” Ian Desmond said. “We’re way beyond” celebrating a wild-card spot.

The Nats clinch is a lovely story, but also a foregone conclusion for weeks. They aren’t merely a good team that will now play at least one postseason game.

Objectively, the Nats are so excellent that 13 big-league franchises have seen only one team as superior as they are, or none at all, in the last 50 years.

After Thursday night’s 4-1 win over the Dodgers, the Nats are on pace to win 99 games. That’s one win above a symbolic baseball number: 98 wins. Why 98? At that threshold you win more than 60 percent of your games (.605) In other major sports, that rate of success is seldom noticed. But in baseball, it is a landmark.

Since both leagues went to a 162-game schedule in 1962, the glamorous Red Sox have had just two 98-win teams. The Dodgers haven’t had even one .600 team since 1977. Since 1900, the Phillies have had just three .600 teams. The Rangers, who’ve been to the past two World Series, have never had a .600 team in franchise history back to their Washington Senators days.

In those 50 seasons, seven current franchises have never won 98 and six others have only had one such .600 season. That’s 13 teams, or nearly half the entire sport.

The point is not to guess the Nats’ exact win total. The idea, entering this last two vital weeks, is to have a general sense of how well this team has played to this juncture so that, whatever pennant-race fate comes next, it can be watched in a sensible context.

The Nats’ season benchmark is now .611. That’s the best in the sport and an altitude which gives us perspective on why there is such a wide disconnect between the Nats’ confident sense of themselves and the town’s skittish, is-it-safe-yet viewpoint. By D.C. standards, this is a ballclub from Mars.

The reason for the gulf may start with Johnson. All this seems so normal to him. Over his 16 seasons of managing, his teams have averaged 91 victories. This is his fifth team with a record over .600. As a player, he started on teams that won 97, 101, 108 and 109. “That was fun,” said Johnson of Thursday’s postgame revelry. “But winning your division is all that matters. In the new format, I don’t want this” wild card.

For now, the giddy misunderstanding will have to continue between a delighted town and the Washington team itself, which has a limited sense of D.C.’s baseball blues but a clear view of its own impressive future.

Let’s pretend we’ve just arrived on the scene, don’t know the names, histories or ages of the Nats and just look at their performance. Who are they? Probably not wild cards.

The Nats have allowed the fewest runs in baseball and have the lowest ERA (3.28). Their starting pitchers, after subtracting Strasburg’s stats, still have the game’s best ERA.

As the season has progressed and their lineup’s health has improved, the Nats have gradually moved up from a poor hitting team in spring to one of the more productive. The Nats are now fourth in the National League in runs and second in homers (175). Adjusted for park size, they’d pass the Brewers and be the NL’s top power team. That’s despite losing months of playing time from sluggers.

Final puzzle pieces keep arriving. Drew Storen, who missed three months, iced the clinching win by blowing away the heart of the Dodgers’ order, striking out Matt Kemp, Adrian Gonzalez and Hanley Ramirez, showing them a new sinker and change-up that he’s added to his 43-save repertoire of last season. All three batters looked surprised, then overmatched.

Will this excellent team, so consistent for six months, be the club that shows up for the last two weeks of the regular season and the postseason? No one knows.

Here’s what we do know: Only a very few teams, such as the Yankees and Braves, have regularly delighted their fans with .600 teams in the last 50 years. Most teams are lucky if they can hit that level once every dozen years. It’s not just the 13 teams referenced above — with zero or one 98-win team — that have had a hard time reaching .600. Since ’62, the Angels and Indians have done it twice, the Giants, Tigers and Phils only three times.

On Wednesday, the Nats trailed the Dodgers 6-0. Johnson left just three regulars in the lineup. Yet the Goon Squad erupted for six runs in the eighth inning to tie as a delighted crowd probably thought, “They can’t be this good, can they?”

It’s hard to get our heads around such a question, just as it’s difficult to grasp that the Nats are just a 7-6 finish from a .600 season. But you can’t watch the insane final weeks of this season rationally unless you realize this: They’ve been that good so far.

For previous columns by Thomas Boswell, visit