It might be tough for Vikings to reach 13 victories again next year

The disappointment for the Vikings and their fans of missing out by one game on a chance to not only play in a Super Bowl but do it in U.S. Bank Stadium is enough to leave oodles of regret this offseason.

The longer-lasting regret, though, might come from the recognition of how improbably — and nearly perfectly — 2017 aligned for the Vikings to have success, and how difficult that will be to duplicate.

The NFL is littered with examples of teams that made a big leaps from one year to the next — the Vikings went from eight victories to 13 between 2016 and 2017 — only to experience a natural regression the next season.

There are certainly some exceptions, including the almost always excellent Patriots who are going on nearly two decades of consistency and will face the Eagles in Minneapolis on Feb. 4.

But it will be difficult for the Vikings to win 13 games again next season for a variety of factors. Among them:

• The schedule gets a little tougher next year than it was this year. By virtue of winning its division, Minnesota will face other first-place teams next year (whereas last year the Vikings played other third-place finishers). The Vikings also only had seven true road games in 2017, getting to play the Browns in London in what was officially a home game for Cleveland.

The road slate looks particularly daunting in 2018: at Green Bay, Detroit, Chicago, Los Angeles Rams, Seattle, Philadelphia, New York Jets and New England. I see a lot of quality opponents there, and a lot of long trips to the coasts.

• The Vikings had the best third-down defense of any team since the NFL started tracking that statistic in 1991. Part of that success is surely related to their scheme and the overall strength of the defense, neither of which figure to change much, but even a modest natural regression in that area in 2018 from "historically great" to "really good" could alter the course of some games.

The good news is that the Vikings' 13-3 record was not compiled via some fluke of winning an extraordinary number of close games. ESPN's Bill Barnwell in August correctly pegged a lot of teams from 2016 that were primed for regressions in 2017 — including the Giants, Raiders and Cowboys. He also correctly forecast the Jaguars and Eagles were primed for massive improvements.

Several factors went into that assessment, but a big one is point differential. The Vikings' expected won-loss record based on point differential in 2017 was 11.7-4.3, which is worse than their actual 13-3 record but not drastically different.

The Vikings also should have dynamic running back Dalvin Cook back for 2018 after he missed much of last season with a torn ACL, and virtually all of their top defensive players are back as well.

But given next year's schedule, the likelihood of a downtick in third down defense and of course the uncertainty the Vikings face with their quarterback and offensive coordinator, some regression is likely.

That would truly be a feat.