Correction: A previous version of this column said Washington is the only city that has teams with winning records in all four major pro sports.

Coach Barry Trotz, right, on his team’s postseason hopes: “Team history is an obstacle. You have to go through it, or over it, too — not around it. You have to be in the moment, not let it control you. Why are all our fans so nervous? They aren’t playing the game.” (Minas Panagiotakis/Getty Images)

Right now, only two major markets have teams with winning records in all four major pro sports. One is Boston and the other is Washington. Taken as a group in regular seasons, the Capitals (37-11-6), Wizards (31-21), Nationals (95-67) and Redskins (8-7-1) are at a high point in D.C. history.

The other huge chunk of truth is that none of those teams have won a title in a quarter of a century. Yet only a jaded pessimist would deny the possibilities now.

In particular, the Capitals have turned “on fire” into understatement. Since New Year’s Eve, they’re 17-2-1 with a ridiculous 50-goal margin in 20 games. If they stay on their NHL-leading pace (122 points), they would have three of the four 120-point seasons since 1999, when the league started giving a point for overtime losses.

[Bog: D.C. has more combined NBA and NHL wins this season than any other city]

1 of 12 Full Screen Autoplay Close Skip Ad × United Arab Emirates female hockey player meets and practices with the Washington Capitals View Photos Fatima Al Ali, a member of the UAE women’s national team with sick stickhandling skills, attended the Capitals’ practice at Kettler Capitals Iceplex in Arlington, Va. Caption Fatima Al Ali, a member of the UAE women’s national team with sick stickhandling skills, attended the Capitals’ practice at Kettler Capitals Iceplex in Arlington, Va. Feb. 8, 2017 United Arab Emirates native Fatima Al Ali fires shot at the goal on a pass by the Capitals’ Alex Ovechkin, center left. In November, Capitals great and team ambassador Peter Bondra traveled to the UAE to serve as a coach at the Pavilkovsky Hockey School in Abu Dhabi. During the trip, Bondra met Al Ali, a member of UAE’s women’s national team, who dazzled him with her stickhandling skills. John McDonnell/The Washington Post Buy Photo Wait 1 second to continue.

Capitals Coach Barry Trotz and GM Brian MacLellan look at events in all sports for patterns in championship runs. Right now, there’s a huge one.

For a year, one title after another has been won by a team that seemed stone dead. Sports might as well hold up a sign: “Lesson to be learned here.” All teams can be beaten. But some teams, even though they lose at times, are unbreakable.

Or they look awful darn close — spooky Tom Brady close — to unbreakable. Those teams, such as New England in Super Bowl LI, create the impression that, even trailing by 25 points with 24 minutes left, you can’t crack their willpower or make them misplace their identity, either in playing style or mental toughness.

This kind of team self-confidence is one of the most powerful weapons in sports. Momentum “and belief can do magical things,” Trotz said.

The Cubs and Cavaliers came back from 3-1 series deficits to win MLB and NBA crowns. Villanova basketball and Clemson football rallied to win NCAA titles.

Often, more than one team seems “unbreakable.” When they meet, such as the Indians and Cubs wrestling to the 10th inning of Game 7, we get classics.

MacLellan and Trotz think they have built such an unbreakable team now. Oh, they know the Penguins have one, too. Maybe a couple of other clubs as well, come the playoffs. But the Caps without huge cracks in the spring would feel unique.

“We’ve had three years now for this coaching staff, system and culture,” MacLellan said Tuesday after the Caps posted back-to-back 5-0 wins. “In the past, when we broke, there was a reason. Last season, we were good. But at that level [of going for titles], if you have one little weakness, it gets exposed.”

That one weakness was lack of depth. “The Penguins beat us with their third line. We couldn’t sustain a high enough level of play for long enough,” Trotz said Monday. “We never got exposed by anybody — except by Pittsburgh.

“Now we have that third line,” Trotz said after seeing newly acquired center Lars Eller and winger Brett Connolly combine with emerging young star Andre Burakovsky for a dazzling 20 goals in the past 15 games.

[Bog: The home cooking was perfect for Caps and Wizards in January]

The Capitals trust all four lines enough to cut the playing time of stars Alex Ovechkin and Nicklas Backstrom. The Caps think better-rested players are one reason they have the fewest injuries in the league.

“By having four [trusted] lines, we play faster,” Trotz said of the ramped-up pace that, for six weeks, has had opponents behind early, exhausted by midgame and blown out of the building late.

Clobbering everybody is fun — 89 to 39 in the 17-2-1 streak — but that won’t happen in the playoffs. How will the Caps respond in their desperate moments? Like the Patriots, Cavaliers and Cubs?

They never have, except for one trip to the Stanley Cup finals. But they now have a much-improved room built around lose-hard vets Justin Williams, Brooks Orpik and Matt Niskanen. The ultimate symbol of NHL psychological stability, Vezina Trophy-winning goalie Braden Holtby, is the Capitals’ semi-unsung MVP; the once-all-offense Caps have the lowest goals against average in hockey.

“Confidence and team identity flows out from the goal and through the defensemen,” MacLellan said.

Still, what happens to the Caps in Desperation Time, when the worst response is to seem desperate? Trotz has asked almost every coach who has reached or won a Cup in recent times about the travelogue to get there.

“They all say the same thing,” Trotz said. “ ‘We almost got knocked out in one of the early rounds. But somehow we didn’t. Then we turned it around.’ ”

“You can’t go around obstacles. You have to go through them or over them,” said Trotz, whose team made some progress against the Penguins last season when, after falling behind three games to one, it won Game 5 and came back from a 3-0 deficit to send Game 6 into overtime — before losing.

The Capitals, like the Wizards, Nationals and Redskins, face an additional obstacle, one that fans of the Cubs knew only too well: a curse.

[Bog: The Capitals and Wizards are both in first place. That never happens.]

“Team history is an obstacle. You have to go through it or over it, too — not around it,” Trotz said. “You have to be in the moment, not let it control you.” He chuckles. “Why are all our fans so nervous? They aren’t playing the game.”

After 25 years of breakage, a fan base with shredded nerves is inevitable. The idea that Washington fans would even aspire to teams that seem “unbreakable” is, well, unthinkable. Yet it’s essential.

At this point, perhaps only the Caps are close enough, in talent, record, experience and depth, to be taken totally seriously in a championship discussion. Maybe only one question remains: Can they become one of those rare teams — perhaps only a couple of them per sport per year — that makes its fans and its foes think, “They’re not unbeatable, but they sure look unbreakable.”

No one has ever said such a thing about the Washington Capitals. But to get a Cup, that’s almost certainly going to have to change.

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