Evolving Hockey’s expected goal model determines the likelihood that unblocked shot attempts become goals based on a number of variables, such as where the shot was taken from and the type of shot. For example, a slap shot from the blue line might be assigned a value of 0.03 indicating that it would become a goal only one out of every 30 times, while a wrist shot taken right in front of the net might be expected to be converted on one out of every four attempts and, therefore, would be given a value of 0.25 expected goals. In this example, it would take roughly eight slap shots from the blue line to match the value of the wrist shot taken from in front of the net.
Goals Saved Above Expected (GSAx) tells us how good or bad a goaltender is relative to league average based on the shot quality the goalie has faced. GSAx is calculated by subtracting the total goals that a goaltender has conceded from the number of expected goals he has faced. Let’s take a look at the good, the bad and the ugly through the lens of modern hockey statistics, by division.