In order to account for different schedule lengths, roster sizes, and scoring environments, some statistics have been adjusted. All statistics have been adjusted to an 82-game schedule with a maximum roster size of 18 skaters and league averages of 6 goals per game and 1.67 assists per goal.
We will use Gordie Howe's 1952-53 season as an example, a season in which Howe scored a career-high 49 goals.
The first step in this process is to calculate a schedule adjustment for each player. In order to do this, divide 82 by the number of scheduled games per team. In 1952-53 the NHL played a 70-game schedule, so the schedule adjustment is 82 / 70 = 1.17.
The roster size adjustment is computed by dividing the maximum roster size for the season in question by 18. Teams were allowed to carry a maximum of 16 skaters at home and 15 skaters on the road during the 1952-53 season, so the roster size adjustment is 15.5 / 18 = 0.86.
Next calculate the era adjustment, which we will do by dividing 6 by the league average goals per game without the player in question. In 1952-53 a total of 1006 goals were scored in 210 games. Without Howe this works out to (1006 - 49) / 210 = 4.56 goals per game, so our era adjustment is 6 / 4.56 = 1.32.
Finally, we put everything together. Take the player's actual goals and multiply by the adjustments we computed above. For Howe in 1952-53 this is 49 * 1.17 * 0.86 * 1.32 = 65 adjusted goals.
Once again we will use Howe's 1952-53 season, when Howe had 46 assists, as an example.
First compute the schedule and roster size adjustments as above. The era adjustment is found by dividing 10 (which is the product of 6 goals per game and 1.67 assists per goal) by the league average assists per game without the player in question. In 1952-53 a total of 1513 assists were awarded in 210 games. Without Howe this works out to (1513 - 46) / 210 = 6.99 assists per game, so our era adjustment is 10 / 6.99 = 1.43.
Adjusted assists are then computed by multiplying the player's actual assists by the three adjustments. For Howe we get 46 * 1.17 * 0.86 * 1.43 = 66 adjusted assists.
Adjusted points are simply the sum of adjusted goals and adjusted assists.
To compute adjusted goals against average, first figure the player's unadjusted goals against average, then multiply by an era adjustment. The era adjustment is found by dividing 3 (our base goals against average) by the league goals against average without the goaltender in question.
For example, in 1993-94 Dominik Hasek allowed 109 goals in 3358 minutes, a goals against average of (109 / 3358) * 60 = 1.95.
The league totals were 6927 goals in 132362 minutes, giving a league goals against average (without Hasek) of ((6927 - 109) / (132362 - 3358)) * 60 = 3.17. Thus the era adjustment is 3 / 3.17 = 0.946.
Appyling this to Hasek's goals against average, we get an adjusted goals against average of 1.95 * 0.946 = 1.84.