You weren't chased away by a post dealing with hockey and Sabermetrics? Good for you! Then you've probably watched enough icepuck to realize that save percentage is a pretty weak measure of a goalie's ability. All shots are not created equal—a slapper from between the circles is going to be harder to block than a prayer from the goal line in the corner. So what if there were a way to gauge a goalie's skill in light of the types of shots he faces?
A statistics professor at St. Lawrence University has come up with defense independent goalie rating, or DIGR. Every shot from last season was mapped, with a goalie's save percentage against each location calculated. DIGR essentially normalizes the defensemen and gives a hypothetical save percentage for how a goalie would have fared against every shot that every goalie faced.
Obviously, it's not an exact science. Not even in baseball can a statistic can be the be-all end-all of metrics, as DIPS and DERA and DICE battle with each other, and FIP and xFIP. And DIGR doesn't seem to take into account screened or deflected shots. But it's a good sign that the goalies with the best DIGR were considered the best goalies in the NHL last season: Tim Thomas was first, Roberto Luongo second. And bringing up the rear is Nikolai Khabibulin. (Here is where a crusty old sportswriter pipes up that he doesn't need some newfangled math to tell him that Khabibulin is crap.)
There's No Defense for a Bad Goalie [Wall Street Journal]
DIGR: A New Stat Removes the Flaw From Save Percentage [Backhand Shelf]