When the Caps fired former general manager George McPhee and head coach Adam Oates after missing the playoffs in the 2014 season, Ted Leonsis hired Barry Trotz as the new head coach before he hired a new general manager. (Brian MacClellan was hired soon after.)
Trotz came to Washington to change the culture by emphasizing defense and discipline. Trotz instilled in his new captain Alex Ovechkin that in order to win, every player and coach had to trust each other and work together. Trotz got all the guys in the locker room “pullin’ on the same rope” as he led them to the second round of the playoffs three straight years before winning the first Stanley Cup in Capitals franchise history, beating Vegas in 2018.
After the Washington Capitals celebrated their victory first Stanley Cup championship with their fans on the streets and in a fountain, the front office announced that they were letting head coach Barry Trotz leave to pursue other opportunities in the NHL due to a contract dispute. Fans, still in the glow of finally winning the Stanley Cup suddenly felt the all too familiar gut punch of despair.
Finally, the Caps had won the Stanley Cup only to let the coach who had finally led them there walk. The Caps failed to advance past the first round for the next seven years, missing the playoffs altogether twice in that span. Capitals faithful was left to wonder, what if?
What if Trotz had come back for another run with Ovi and the boys?
The Capitals upgraded their roster before and during the 2018-19 season adding roster added Nick Jensen, Carl Haglin, and Nic Dowd, so they were well equipped for another deep playoff run. Trotz knew how to unlock Evgeny Kuznetsov and would inspire another amazing post season performance from talented Russian in the 2019 playoffs.

In this alternate-reality Spring of 2019, the Caps beat the Hurricanes in the first round in 6 games behind red-hot Evgeny Kuznetsov, before quickly dispatching the Canadiens in 6 games thanks to more heroics from Alex Ovechkin.

(Note: Since Trotz didn't leave DC, he was hired to coach the Islanders, so they missed the playoffs in 2018-19. Montreal made it instead, who beat Pittsburgh in the first round.)
The Caps then beat the Bruins in five games, with Holtby pitching three shutouts before moving on to the finals to beat the St. Louis Blues in six games to win their second straight Stanley Cup in front of the home crowd on a game winning goal by Conn Smythe winner Kuznetsov. (Sorry, Blues fans, but this is my alternate reality.)

There would have been another celebration in the streets of DC, as the players raised the Cup all over the District, and for the second time in a fountain. The fountain celebration would lead to a new Capitals alternate uniform design, which features a fountain with the US Capital building silhouetted behind.
If only it had been.
