They won 18 more games than they had last year, 17 more than they had in any of their previous seven seasons in Washington. After finishing with the best record in the majors, 98-64, they have home-field advantage throughout the National League playoffs and, thanks to the NL’s All-Star Game victory, in the World Series, too.

That’s all great news for the Nats. The major question is whether they’re a one-year wonder like the 2003 Miami Marlins, who have averaged a fourth-place finish in the NL East in the ensuing nine years, or are they built for the long haul like the Atlanta Braves, who won 14 division titles, four NL pennants and a World Series from 1991-2005.

The Nats’ youth bodes well. Among their key players, only right fielder Jayson Werth and first baseman Adam LaRoche, who might not return next year depending on whether management exercises his option, are older than 30. Left fielder Michael Morse and set-up man Sean Burnett reached that milestone this year. Catcher Kurt Suzuki and fifth starter Edwin Jackson, who might not be back in 2013, hit the big 3-0 late next year. Morse and Burnett are signed through next season.

Only five other players who spent the entire season in Washington are even eligible for arbitration this winter and free agency after 2013: third and fourth starters Jordan Zimmermann and Ross Detwiler, demoted closer Tyler Clippard, backup catcher Jesus Flores and long reliever Tom Gorzelanny.

That means that All-Star pitchers Gio Gonzalez and Stephen Strasburg, closer Drew Storen, All-Star center fielder Bryce Harper, third baseman Ryan Zimmerman, All-Star shortstop Ian Desmond, second baseman Danny Espinosa, Werth and Suzuki are all tied up for at least two more seasons. That’s a heck of a foundation of talent not going anywhere.

Of that list of nine locked-up players, only Gonzalez, Zimmerman and Werth have track records long enough to say whether 2011 was a career year for any of them.

Werth’s .300 batting average was a career-high, but his five homers were way off as the broken wrist that cut his season in half reduced his power. Zimmerman’s .282 average was a down a little, but his power rose. Gonzalez, a serious Cy Young Award candidate, had his best season in his Washington debut, but he was an All-Star in Oakland in 2011 so it wasn’t like his performance was a total outlier.

Of the players not sure to be on hand in 2014, LaRoche’s power numbers – team-leading totals of 33 homers and 100 RBI – were career-highs, but just barely. Morse had better run production than usual despite missing so much time with a back injury. Burnett’s 2.38 ERA was off the charts, but so was Clippard’s 3.72 mark in the wrong direction.

Jackson’s ERA of 4.03 was better than usual but reliever Michael Gonzalez’s 3.03 was worse. Gorzelanny’s 3.38 was spectacular as was reserve outfielder Roger Bernadina’s .291 average. Suzuki’s numbers for Washington were terrific, but he was only here for 43 games. And Flores might not even make the roster next spring if Wilson Ramos is recovered from the knee injury that ended his 2012 season in May.

And as mentioned, Desmond, Espinosa, Zimmermann, Strasburg, Detwiler, Harper, Storen and jack-of-all-trades Steve Lombardozzi haven’t been around long enough to know if 2012 was a high-water mark for any of them, although that seems unlikely given their youth.

At 19, Harper set major league records for total bases (254) and extra base hits (57) by a teenager while his 98 runs and 22 homers were second-most and his 18 stolen bases were third-most.

At the other end of the Nats’ age spectrum is manager Davey Johnson, who’s 50 years Harper’s senior. Johnson’s 98-64 record in 2012 matched his marks in his second seasons with the New York Mets and Baltimore Orioles. Since Johnson managed the Nats for just over half a season in 2011 (83 of 161 games), we’ll call this his second season in Washington, too.

Johnson just missed winning the NL East with New York in 1985 before leading the Mets to the World Series title the next year. He never got a third season in Baltimore, much to the embarrassment of the Orioles, who didn’t get back to the playoffs until this year. Whether the Nats win the World Series or not this month – and the team with the best record won just two of the past 13 championships – the decision on whether he’s back in the dugout in 2013 at 70 is all his.

As competitive as Johnson was as a second baseman in the 1960s and 1970s and has been as a manager since, why would he walk away from a team whose best days, amazingly enough, might still be ahead?

David Elfin began writing about sports when he was a junior at Bethesda-Chevy Chase High School. He is Washington’s representative on the Pro Football Hall of Fame selection committee and the author of seven books, most recently, “Washington Redskins: The Complete Illustrated History.” A pre-game regular on 106.7-The Fan the last two Redskins seasons, he has been its columnist since last March. Follow him on Twitter: @DavidElfin