“As far as the home-field advantage thing goes, it doesn’t matter,” says Jayson Werth. (John McDonnell/THE WASHINGTON POST)

On pace for 99 wins and owners of the best record in baseball since the first week of August, the Washington Nationals could enter the postseason with a perverse reward for towering over the National League.

If the current standings hold, the Nationals will watch a one-game playoff the night of Oct. 5 to determine which city they fly to for the start, two days later, of their divisional round playoff series. Fans back home will wait another five days for a playoff game at Nationals Park.

Barring an utter collapse, Washington’s first baseball postseason since 1933 will coincide with an odd, potentially punitive one-year scheduling quirk. Prompted by a late change to the playoff format, the top two seeds in each league will begin the playoffs on the road. The Nationals currently hold a 11 / 2-game lead over the Cincinnati Reds for the NL’s top seed. If they maintain their position, they would still play the first two games of a five-game N.L. division series on the road, against the winner of the one-game wild-card playoff.

This winter, Major League Baseball introduced an extra wild-card team for each league. The league aimed, at once, to add more teams into the playoff mix and inject more urgency into division races. Every season since 1995, three division winners and one wild card essentially started the postseason on equal footing. Now, two wild-card teams play a one-game playoff for the right to reach the division series.

The rationale has worked. In the National League, teams such as the Phillies and Brewers are still playing meaningful games in what would otherwise be all-but-lost seasons. In the American League East, the Orioles and Yankees are in a nip-and-tuck race to avoid the play-in game.

But the timing of MLB’s decision introduced a one-year problem. The league announced the 2012 schedule in September of 2011, which is standard. The new playoff format was resolved in the new collective bargaining agreement, which was finalized in December.

The league had not factored the one-game playoff into its 2012 schedule. And MLB did not want the World Series to extend deeper into November. That convinced the league to play three consecutive home games at one park. No one wanted to risk a playoff team playing no games at home, and so the league settled on the current, imperfect format.

It is possible that the team with the best record in the league will play only one home playoff game. For home-field advantage to favor the higher seed, the series would have to reach the full five games.

“As far as the home-field advantage thing goes, it doesn’t matter,” right fielder Jayson Werth said. “All bets are off once you get there. Obviously, playing in front of your fans, your crowd, is nice. But it doesn’t mean you’re going to win. We’re a good road team. We’re a good home team. Either way, they got to throw the ball over the plate and we got to hit it.”

The 2-3 format is not new. For the first three years of the divisional round, baseball used the same scheme. But for the past 14 seasons, MLB laid out a postseason scheduled with a 2-2-1 format for the division series round — two games at the top seed, two games at the lower seed and the decisive Game 5 at the top seed. The league will reinstitute that format in the future, beginning next year.

If the Nationals hold on to the league’s best record, they will not even know their opponent, or the site of their opening game, until less than 48 hours before first pitch. The Dodgers remain in the hunt for the second wild-card spot, which means the Nationals could have to plan and make a cross-country flight on the turn of one game.

Nationals coaches say the schedule would not have a major impact on their preparation. The Nationals have had scouts following all their potential playoff opponents in recent weeks. And since they have played all of the wild-card contenders in September, they will have fresh impressions of their opponent anyway.

There is another change that could impact the Nationals in the first round. In the past, teams from the same division could not face each other in the first round. Now, the team with the best record plays the wild-card winner, no matter what. So the Nationals could play the Atlanta Braves, who lead the wild card race by 71 / 2 games.

If the current standings hold, the Braves and St. Louis Cardinals would play in the one-game playoff, with the Cardinals holding a one-game edge over the Dodgers. The Nationals announced Tuesday that they will begin selling individual playoff tickets Friday at 10 a.m.

Nationals Manager Davey Johnson did not want to address the format with games remaining in the regular season, calling it “total conjecture.” He professed he had not mulled the Nationals’ playoff schedule.

“Ask me when it happens,” Johnson said. “I’ll tell you how horse [manure] it is.”