WASHINGTON — For the Washington Nationals, the trick to winning so much this year was staying loose.

They went out of their way to celebrate every moment. They danced in the dugout. They clapped their hands together to do the “Baby Shark” whenever their team got a hit. They donned cheap pink- or yellow-tinted sunglasses, and their fans were more than happy to join their goofy party.

But then came Games 3, 4 and 5 of the World Series at Nationals Park, the first time the city hosted the Series in 86 years.

And in seeped the pressure.

“I’m wondering if we were pressing a little bit, just with the atmosphere that was here in Nats Park, how good the fans were,” pitcher Sean Doolittle said on Sunday night, after the Nationals lost their third game in a row to the Houston Astros. “Sometimes you really want to put an exclamation point on the situation to bring the crowd to their feet. I’m wondering if that played a role in it.”

Doolittle said he felt terrible that the team couldn’t deliver for the fans and that it’s frustrating and “it stinks.” But he and his Nationals don’t want their supporters to give up hope for a World Series title in Washington this year, as improbable a request as that may seem.