Well, I checked a few stats now and by my calculations, at least in the last years, it is a trend, but not as clear-cut as it may sound according to Jason Cole. The last three years, the 0.6 yards-per-play differential held up, but for example, from recent Super Bowl winning teams, the Giants
(against a real stat monster, the 17-1 Patriots who posted a ridiculous 1.3 yards-per-play differential), the Ravens
and interestingly, all three recent Patriot teams
all fell short of that marker. The Giants even had the same exact 0.1 yards-per-play differential the Niners currently boast.
This means from the last ten Super Bowl winners, six had the differential, but four did not
. Sure that is a trend, but in my opinion, a pretty weak one (it is only slightly above .500, after all). Why you would use that as your all-telling, final stat to determine or dismiss a championship team, I don´t really get.
It is not a good, strong indicator and even worse, a lot of teams scoring well at this stat fizzled out pretty badly, which makes you look kinda foolish if you only rely on that stat.