The Vikings had a truly exceptional year in 1998, going 15-1 and setting an NFL record (at the time) for points in a season with 556.

I tend to think of that season as the demarcation of an era — the arrival of Randy Moss and the start of a stretch that saw the Vikings make three NFC title games in a 12-season span. The tendency in that regard is to then think of that season starting a stretch of 20 seasons (including this one) that has been mostly positive for the Vikings.

But after watching this year’s Vikings fall to 2-2 Sunday, extending the most roller-coaster four-game sample possible, this thought occurred: What the Vikings have really excelled at since that 1998 season is making what has cumulatively been quite average seem extraordinary.

This was just a theory until a visit to Pro Football Reference and some quick math confirmed the suspicion. With Sunday’s 14-7 loss to the Lions, the Vikings now have a regular-season record from 1999 to the present of 146 wins, 145 losses and one tie.

Of the 18 completed seasons in that span, they had eight winning seasons, seven losing seasons and three seasons of exactly 8-8. They made the playoffs seven times, going 4-7 in postseason games.

They employed Moss, Cris Carter, Daunte Culpepper, Adrian Peterson, Brett Favre, Jared Allen and countless other defensive stars in that stretch. They also had seasons derailed by scandals, injuries and general quarterback incompetence. Very few seasons — any? — could be considered mundane or boring.

Moreover, the 2016 season and the first four games of 2017 have been a microcosm of the 1999-present Vikings.

Last year’s squad, as everyone is painfully aware but I will remind you anyway, was beset by a devastating knee injury to quarterback Teddy Bridgewater in the preseason … only to trade for Sam Bradford and start 5-0, fueling Super Bowl talk … only to crash back to earth with several excruciating close losses behind a crumbling offensive line, dooming the Vikings to an 8-8 finish.

This year already there has been an extreme high or low every week. The pendulum swung high in Week 1 after Bradford delivered perhaps his best game as a pro, only to watch it go equally low the next week when Bradford’s knee injury forced Case Keenum into action in a disheartening loss at Pittsburgh.

That loss diminished expectations significantly going into Week 3, only to have Keenum register statistically the best game of the first three weeks of this season by any quarterback (at least in terms of Total QBR) in a win over Tampa Bay.

That led to plenty of optimism going into Week 4, particularly with the way rookie running back Dalvin Cook had looked. So of course Cook was injured Sunday as the offense scored just seven points.

Even by the standards the Vikings have set over the past two decades, this year feels particularly rocky so far.

But overall, it’s all just an extension of the same theme: an equal amount of winning and losing, delivered in the most turbulent way possible.