When do you know?

When do you admit that you were wrong and move on? When do you fire the team president, the general manager, the coach or the manager?

When do you give up on your quarterback or decide you must add a top reliever, expenses to the wind, to fix your bullpen? When do you say, “We won’t make it this year,” then deal stalwarts for prospects at the trade deadline?

When do you give up on executives, managers, coaches or key players in whom you’ve placed enormous responsibility, faith and franchise reputation?

There is no tougher problem in pro sports, or one with which Washington fans have been so constantly familiar in every game for at least the past 50 years.

You can mess up in either direction. The Wizards just fired GM Ernie Grunfeld — 16 years too late. Dan Snyder once took advice from Vinny Cerrato — for a decade. Now, it’s Bruce Allen who has Dan’s ear in perpetuity. Just can’t pull that trigger.

But the Capitals barely tried to keep coach Barry Trotz after he won their only Stanley Cup and the Nats didn’t rehire Dusty Baker after he won 95 and 97 games. Those quick twitches don’t look so good now.

No one has yet written The Book, or even a rough draft, on the proper protocols for such decisions. Each case is fascinatingly and infuriatingly unique.

Right now, the Nats are the team at a crossroads.