With 102 points through 80 games, Patrick Kane of the Chicago Blackhawks is poised to win the Art Ross Trophy as the N.H.L.’s top point scorer. His superlative season has evoked achievements from an earlier era. He is the first American-born player with a 100-point season in 20 years. His 26-game point streak earlier in the season was the longest since 1992-93.

But his league-leading numbers also reflect how far removed hockey is from its offensive heyday.

Thirty years ago, Wayne Gretzky set a single-season N.H.L. record with a mind-boggling 215 points in 80 games for the Edmonton Oilers, completing the feat with an assist on a Marty McSorley goal in the season finale against the Vancouver Canucks on April 6, 1986.

That season, N.H.L. teams averaged 3.97 goals apiece per game. It was the second-highest average since the league’s 1967-68 expansion to 12 teams from six. The peak was 4.01 in 1981-82.

At the 30th anniversary of Gretzky’s seemingly unbreakable record, another statistic stands out: N.H.L. scoring has continued to decline since the 1985-86 season, never topping the 3.97 mark.