In his last ten outings, Braden Holtby has posted an impressive 7-2-1 record, piling up victories as he has all season long and keeping pace with Martin Brodeur's single-season win record.

Over that same stretch, however, Holtby has quietly posted a save percentage below .900 (okay, .899) and a goals against average above three (3.17)... hardly the Vezina front-runner numbers we've come to expect from the 35 starts that preceded this span (.933 and 1.91, respectively, to be precise).

Of course, both slumps and regressions happen, and they're not the same thing - and this is a pretty small sample we're looking at. Heck, if the Wild's third goal last week was correctly overturned, that save percentage bounces up to .903. But should we be concerned that, in his last eight outings, Holtby has as many games in which he's allowed three or more goals (five) as he had in his previous 20 appearances?

To be clear, Holtby's recent numbers aren't the result of a bad (or unlucky) penalty kill. He's actually stopped 88.7 percent of the shots he's seen there (47 of 53), which is a tick above the 87.9 percent he had in his first 35 games. No, this dip is coming at five on five - and it's not exactly comforting that the current ten-game stretch represents basically the lowest adjusted five-on-five save percentage of Holtby's career outside of the Adam Oates-driven disaster in the middle of the 2013-14 season (via war-on-ice.com):

Interestingly enough, the drop in his numbers comes at a time when the team's shots allowed (the red line below, with save percentage in black) have been generally coming down:

Look at that chart and it's hard not to think that there's some "there" there to more shots-faced being either beneficially to Holtby individually or generally inflating a goalie's save percentage by adding more low-quality chances-against (i.e. easy saves to goose the number). But speaking of low-quality chances, that's where Holtby has been dinged lately. Take a look at five-on-five save percentage by "danger" (low-to-high):

To put that all in perspective, here are Holtby's numbers before and after January 15 (our point of delineation here) and the League-wide numbers since the start of last season:

NHL, 2014-16 Holtby, pre-1/15 Holtby, post-1/15 Sv%L .974 .986 .948 Sv%M .927 .939 .902 Sv%H .839 .870 .836

The drop-offs are across-the-board, although we can ignore the recent ten game specifics, to an extent - that "low" dip represents all of five goals-against (high is ten, medium is four). But this hasn't simply been a regression, it's been a slump - in each of the three categories, Holtby has performed below the League average (just barely on the high-danger shots, though... so that, theoretically, looks more like regression, though there's reason to believe that Holtby's "true talent" is somewhat above average). Of course, again, this is a relatively short span, less than a quarter of the season-to-date.

All of this circles back to the question of whether or not we should be concerned.

If you thought that Holtby would continue to post the kind of numbers he did through mid-January, you might be. But those numbers, while terrific, were likely unsustainable over the course of the season; to the extent you understood that (and understand how volatile small samples can be), this regression or slump or over-correction or whatever you want to call it is easier to brush off.

That said, it's certainly something to keep an eye on going forward, especially in light of his heavy workload. After all, Brodeur's win record isn't the goal this season, and Braden Holtby is the first person that would tell you that.