Scoring 50 goals in the first 50 games of an NHL season has been done eight times by five players: Maurice Richard for the Montreal Canadiens (1944-45), Mike Bossy for the New York Islanders (1980-81), Wayne Gretzky (1981-82, 1983-84, 1984-85) for the Edmonton Oilers, Mario Lemieux (1988-89) for the Pittsburgh Penguins and Brett Hull (1990-91, 1991-92) for the St. Louis Blues.
Because the game has changed drastically over the years, it's difficult to find an exact comparable for Pastrnak's start, but Hull's most recent example with St. Louis may prove similar. For context, when Hull scored 50 in 50 in back-to-back seasons, the League average in goals per game per team was 3.46 and 3.48 respectively. Through 437 games this season, teams are averaging 3.03, the highest total since 2005-06 (3.08).
Hull scored his 50th goal of the season in St. Louis' 50th game, against the Los Angeles Kings on Jan. 28, 1992. Through 28 games that season, Hull had 24 goals, including seven on the power play. Pastrnak has 12 goals on the man-advantage, where the Bruins rank second in the NHL with a power-play percentage of 30.9 (the Edmonton Oilers are first at 31.0). When Hull scored his 50th goal, he had 15 power-play goals and the Blues had a power-play percentage of 19.8. Pastrnak is on pace to score 21 power-play goals through 50 games, which would be the most in that span since Michel Goulet of the Quebec Nordiques (1985-86) had 22 in his team's first 50 games; Bossy also had 22 power-play goals in his first 50 games with the Islanders in 1980-81.
It's not outlandish to suggest that the Bruins could continue to produce around 30 percent on the power play through their 50th game; the Tampa Bay Lightning had a power-play percentage of 29.8 through 50 games last season, and the Bruins were at 27.3 percent.
Not even a lower-body injury to center Patrice Bergeron has slowed Boston's power play. Bergeron, who is second on the Bruins with 23 power-play shots behind Pastrnak (31), has missed the past five games, but the Bruins are 3-for-10 on the power play during that span. Pastrnak has one of those goals.