– The home field is supposed to be an advantage in sports. Players sleep in their own beds. They keep their normal routines. Umpires might be friendlier. Whatever quirks exist on the playing field are familiar. The fans cheer you, not your opponent.

The 2019 World Series, however, has flipped the concept of home-field advantage entirely on its head. The road team has won all six games, the latest Tuesday with the Washington Nationals' 7-2 victory over the Houston Astros that forced a winner-takes-all Game 7 late Wednesday night.

It was a rarity that transcended baseball: According to ESPN Stats and Information, the road team had never won the first six games of a postseason series in the history of Major League Baseball, the NBA or the NHL — until now. Home-field disadvantage, perhaps.

"It's weird, really," Nationals manager Dave Martinez said after Tuesday's game. "I mean, we can't explain it. I know we were trying to win games at home and just couldn't do it."

It is rare to see something entirely new in baseball at all; there have been so many games and so many possibilities for randomness. More than 670 World Series games have been played in major league history since 1903. (The best-of-seven format began in 1905, with a few exceptions.) Why did this unusual phenomenon happen now, with these teams?

Players and managers on both sides had little wisdom to offer.

"It's crazy," Astros third baseman Alex Bregman said. "The road team has just played better baseball in the first six games. I don't know what to tell you about that."

It might simply be a coincidence that the best team in each game of this World Series was the one sleeping in a hotel. The Nationals outplayed the Astros in the first two games in Houston last week. The Astros easily won all three games in Washington, by a combined score of 19-3, to take a 3-2 lead in the series. The Nationals bucked history — a road team had won Game 6 of a World Series only 36% of the time — and continued the unusual 2019 phenomenon behind the powerful right arm of Stephen Strasburg and the potent bat of Anthony Rendon to win Tuesday.

The Astros will have to end the trend Wednesday to win their second title in three years — otherwise the Nationals will be rejoicing over their first Series title in a largely empty Minute Maid Park after Game 7.

"We're waiting until the last game to have it on our side," said Astros manager AJ Hinch of home-field advantage. "We worked really hard to get home-field, and we're happy to play at home. We have no problem playing at home. This place will be rocking. We've won a ton of games in this ballpark. This series has been very weird."

It has. No team in baseball won more games at home during the regular season than the Astros, who went 60-21 there. No team in baseball won more games period, since the Astros' 107 regular-season victories earned them home-field advantage throughout the entire postseason.

The Nationals won 93 regular-season games, entered the playoffs as the first National League wild card team and kicked off a spirited postseason run with a comeback win over the Milwaukee Brewers at home. They beat the Dodgers, the best team in the NL, in Los Angeles in extra innings of Game 5 of their NL Division Series. They swept the St. Louis Cardinals in the NL Championship Series.

Even though the Nationals had to travel to Houston to start the Series on Oct. 22, they were well rested compared to the Astros. The NLCS ended on Oct. 15 while the ALCS ended on Oct. 19 because the New York Yankees pushed the Astros to six games. Still, the Astros finished that series at home, so they did not have the burden of travel between series.

Another factor may be that both teams are laden with veterans, as the Nationals had the oldest regular-season roster in the major leagues this year by average age, and the Astros were third. Nationals first baseman Ryan Zimmerman, who has played 15 big-league seasons, said there was "not really" any difference between playing at home versus on the road. "If you play for a while and been in the league for a while, playing on the road doesn't really bother you," he said.

The effects of home-field advantage might be more tempered in baseball's postseason compared to other sports. Entering this year, home teams have won 55% of the time in the World Series — about the same rate as during the regular season. The Series title, though, has been won by the team with home-field advantage only 49% of the time, according to MLB.