The average number of goals per game is held constant across years. So in higher scoring eras, like the bulk of Gretzky’s career, the average team scored between like 3.7 and 4 goals per game, but you see that dip down through the dead puck era where it’s closer to 2.6-2.8. It means that goals scored in lower-scoring eras are “worth” more than when everyone was scoring like gangbusters.What actually goes into this era adjusting
I think the baseline season they used to translate into concrete numbers (like Ovechkin at 997 now) was one from Gordie Howe’s era.