Defensive linemen Jason Hatcher and Chris Baker were among the last to finish dressing at FedEx Field early Friday after Washington had completed a 45-14 loss to the New York Giants. Coach Jay Gruden called it “a debacle,” though that term ran the risk of slurring innocent debacles everywhere.

“Rude awakening,” the 325-pound Baker said to no one in particular but loud enough for Hatcher to hear. Then, like an antiphonal response in an old-time-religion church, Hatcher echoed back “rude awakening” with the word “rude” drawn out for emphasis.

“We thought we were nice,” responded Baker, shaking his head after that last ironic word.

In the NFL, it takes a while to figure out who’s really “nice” and who’s just naughty. But it sure doesn’t take until Christmas to make up your mind who gets candy canes and who gets lumps of coal. Sometimes, 20 days and four games is enough evidence of a team’s range of play to reach conclusions.

After playing two bad teams that went 6-26 last year, plus a very good Eagles bunch and a mediocre monstrosity of Giants, Washington is a 1-3 team that’s probably on its way to something like 4-12. Although, to give Dan Snyder proper credit for his long, consistent patterns, that may be selling his franchise short. Over time, under most of his coaches, they average out to 5-11 — his grade as an owner.

The Post's Gene Wang and Scott Allen break down the Giants' 45-14 rout of the Redskins. Quarterback Kirk Cousins was responsible for four interceptions and a fumble, while Eli Manning led a balanced attack, throwing for four touchdowns and rushing for one himself. (Randolph Smith/The Washington Post)

That record may continue to be familiar for years to come because these four games have given two incriminating data points: Robert Griffin III breaks easier than the Waterford crystal that some fans sent him when he got married, and Kirk Cousins is a good backup quarterback but fit for emergency use only.

Now we know why Gruden demanded and got a five-year contract despite never being an NFL head man. Snyder’s coaches see their reputations age in Dan Years, so he always has to pay at the beginning for the damage he’ll do by the end. In this case, it seems likely that Gruden will spend years paying for the consequences of Snyder, Bruce Allen and Mike Shanahan spending so much for Griffin and suffering two years of roster atrophy because of salary cap penalties. It was on their watch; they own it.

Thursday night’s loss was, indeed, a rude awakening because it is easy to get fooled early in NFL seasons, either by individual players like Cousins or entire squads, like Washington’s Team To Be Renamed Later.

The result of any one NFL game lends itself to exaggerated conclusions. And no team’s fan base, as well as much of its media, jumps to exaggerated conclusions more quickly than Washington’s. Instead of free pizza, give each fan who ventures to FedEx Field a free towel as a parting gift to wipe the egg off his face after the next city-wide psychotic mood swing.

The team itself tends to the manic depressive in its self-evaluations, swinging from deluded optimism between seasons, which pleases the owner and helps marketing, to the inevitable excessive sinner’s remorse in failure, perhaps in hopes that if you lash yourself maybe the boss won’t.

“We couldn’t have beaten William and Mary tonight. We couldn’t have beaten a high school team,” safety Ryan Clark said. “Every player on that team was better than every player on our team.”

Gruden’s scorched-earth comments, starting with himself, should probably be viewed simply as natural candor, not any agenda. But they fit this team’s Dr. Jekyll-Mr. Hyde self-analysis.

“This was a total team debacle and total team domination by the Giants. They looked better coached. . . .We were abysmal. That was a total butt kicking,” said Gruden, who added that six turnovers and only 14 points were due to “poor play-calling, poor play design, poor protection, good defense.”

A sheepish Baker said, “We’re not as good as we think, obviously.”

Who told them they were good? Find him, lock him up and throw away the key. The only thing a 3-13 team can hope to be the next season is Less Bad. This franchise thinks the natural NFL progression is: We were awful, but now we’re a little better, so by the day after tomorrow, we’re certain to be great.

In a quarter of a season, Washington has already lived out many of the NFL’s misperception tricks.

Soon enough, though, you get a sense of a team’s whole range of outcomes — each a part but only a part of what the whole team actually is. That certainly goes for Cousins, too. He has now started six NFL games and played the equivalent of roughly 32 quarters (or eight games, half a season) throwing 317 passes. What picture is the data beginning to draw?

If Cousins had enough career passing attempts to qualify for the active-player leader board, he would have the worst interception percentage in the NFL (4.7 percent) by a huge margin over the next-worst man on the list, Rex Grossman (3.8 percent). He has more interceptions (15) than touchdown passes (14) and a career quarterback rating of 75.3. Again, if he had enough attempts to qualify, among active players that rating would put him ahead of only two men — Grossman and Mark Sanchez.

Every fall there’s a reality check at FedEx Field. Except for Griffin’s brilliant rookie season, when he traded a knee for 815 yards rushing, it’s as familiar as 1-3 turning into another 5-11. Here we are again.

Where’s Hank Williams Jr. when Washington needs him? Just change those lyrics to: “Are you ready for some . . . baseball!?”