[octothorp]

I think advanced stats for hockey are really in their infancy, compared to where other sports are at, and a lot of that is that hockey is one of the most difficult sports to statistically quantify, and right now, most of these models are incredibly simplistic, including PDO.

But that said, Freidman really screws up part of his explanation: luck does not even out, nor does PDO suggest that it should (although right from its inception, its been linked to the idea of luck evening out). PDO merely suggest that there will be a regression toward the mean, especially for teams that look like outliers. It certainly doesn't make the claim that a team that has been lucky early in the season will be unlucky later in the season, or vice versa. Only that luck, going forward, will be average throughout the league.

But here's the big problem with these scores: there's no reason to expect the order of teams to change, since regression affects all teams; it will simply affect outliers more. There's nothing there to suggest that the Flames won't finish with the second highest PDO at the end of the year. And there's nothing to suggest that the Oilers won't finish with the lowest PDO at the end of the year. You'd simply expect teams to be bunched more closely together at the end of the year.

If all of that is a big problem, then here's the massive, colossal problem with that expectation: the current distribution isn't that out-of-line with the year-end distribution, which typically has the top few teams in the mid 1.20s, and the bottom few teams in the .970s (with the occasional outlier way down in the .960s). So if we expect a similar cluster of scores this year, there's nothing to suggest that Calgary or Edmonton (or any other team) actually will regress toward the mean, since all fall within those expected distributions. Some will regress toward the mean, others will progress away from the mean, others will remain essentially unchanged.

Now, you can break down the two numbers, and argue that there's slightly more regression to the mean for shooting percentage than there is for save percentage. Traditionally, the top teams in the league have a shooting percentage of around 0.10, and both Calgary and Tampa Bay may be expected to trend downward slightly over the course of the year. But they aren't really out of line with the top teams in 2012-13. So it would take a lot more analysis than I could put into it to suggest how likely it is that those numbers will hold and how much they will regress.