Goaltending has a LOT to do with it. Our shots against per game are pretty similar right now (30.8/game last year, 30.2/game this year) but our GAA is way down.
Last year, our goaltending was essentially ~0.900 save %, whereas this year Reimers going at a 0.929% pace... our GAA compared to last year is 2.58 instead of 3.16.. that's a HUGE difference. Our goals for is pretty similar though (2.83 this year, 2.77 last year).
So our GAA is way down, our GF is comparable and our shots against are comparable. It's not an exact science, seeing as quality of shots can differ. But that's really the big difference for me is goaltending. Reimers looked much better, calmer, better glove hand, better rebounds, and its showing on that stats sheet.