It was sloppy, it was ugly, and in the end it was both wildly exciting and exactly as we expected: a Cowboys win, 17-15, over the Vikings in yet another test they and their young quarterback continue to ace.

Give Sam Bradford and the struggling Vikings credit for putting up a helluva fight against the best team in the NFL which, after Thursday's game and the news the Patriots lost tight end Rob Gronkowski for the season, the Cowboys surely are.

The Vikings forced three fumbles, recovered two of them and staged a two-minute drill at the end that put them an errant two-point conversion away from overtime. They held Ezekiel Elliott to 86 rushing yards, his third-fewest of the season and the least since Weeks 1 and 2, his first first two weeks in the league. They were tough, poised and tantalizing close to the win.

And, as we've also come to expect, the officials played a key role with a late-game botched call that cost the Vikings a fair shot. With the game on the line, Bradford took a blow to the head -- a clear penalty -- as he tried to connect on the two-point conversion that would have tied the game. Instead, the throw was high and out of reach, the officials held their flags and the Cowboys found another way to keep their winning streak intact.

Not that Dallas fans should necessarily be celebrating the win.

Michael Irvin may well be right.

His warning last week on a Dallas radio show before the Cowboys' Thanksgiving win over the Redskins may turn out to be prescient, and the Thursday night victory in Minnesota might have been a golden opportunity that got away.

"Instead of a win, I'm really looking for a loss," Irvin told CBS Sports Radio affiliate 105.3 The Fan. "I need a loss in here on the way to the playoffs. To re-identify, refocus. I'm not saying they are not focused in everything -- but I wouldn't have an issue with a loss and a re-shake."

There's something to this. Even the best of teams sometimes need the bitter taste of a loss, and the week that follows, to refine and focus and lock back in. That's doubly true when the two most important players on the team, rookies Elliott and quarterback Dak Prescott, have never experienced playoff football. Winning reveals true winners, but losing shapes them.

Prescott, though he was again impressively poised and again years ahead of what you'd expect from a rookie, fumbled twice Thursday night, losing one. A loss might have helped him look at that tape this week just a littler bit differently.

Don't expect the Cowboys to drop another one. The Vikings game was the last good chance for another Cowboys loss. And while 15-1 looks sexy on paper, just ask the 2007 Patriots how a superb regular season feels if you don't lift that trophy when it's all said and done.

A couple weeks ago, SportsLine laid out the odds for the Cowboys in their last seven games. The Vikings offered the best odds for a Cowboys defeat at +190. The remaining games include the Giants (+350), Bucs (+850), Lions (+900) and Eagles (+850).

So which is it? Are the Cowboys, in rattling off win after win, simply proving they're the best team in the NFL? Are they so good that their youth and lack of adversity this year won't matter come January? Are their rookie QB and rookie running back, that offensive line and the better-than-expected defense such a potent force that this winning streak can carry right into February?

Or is this a team that needs a loss, as Irvin said, to make them their absolute best? A loss to teach those superstar rookies the lessons you can't learn after Week 17 without going home, to remind them things are different in the playoffs, to simply get them to double down on the little things. Is it possible a close win on the road against the Vikings isn't exactly a Herculean effort given that Minnesota has now dropped six of their last seven games?

The answer likely won't arrive until Dak, Zeke and this Cowboys team of the future finds out in the playoffs -- one way or another -- whether that future is now.