I'm confused by these statements. Not sure what I am missing but:
Brett Hall in 1990-91 scored 86 goals in 78 games = 1.103 GPG
W. Gretzky 1981-82 scored 92 goals in 80 games = 1.150 GPG
W. Gretzky 1983-84 scored 87 goals in 74 games = 1.176 GPG
So "statistically" GPG goes to Gretzky. Best single season for goals, again Gretzky.
In Hull's 1990-91 he scored 86 goals, but was not outscored teammates, who were 27 and 25 goals.
Sorry, by "outscored", I meant points (and other things). Not just goals. I was saying that in terms of
overall seasons by forwards, Hull's 1990-91 probably isn't even a top-20 all time season.
However, in terms of goals-only (if there is such a thing as "goals only"), I pick Hull in 1990-91 as the most impressive goal-scoring regular season in NHL history, or at least since 1967 expansion.
Yes, Gretzky had two seasons of better GPG, and needless to say Gretz's top 10 or 12 seasons are all better than Hull's best, overall. But I think Hull is more impressive
purely in terms of goal-scoring because League-scoring was slightly lower in 1991 than in 1982 and 1984, and also because St.Louis in '91 was not an offensive juggernaut (though I suppose they were strong enough, at 4th-overall in offense). Anyway, Hull (with Oates) had to carry the team offensively, as, after Brett's 86 goals, the next-best goal-scorer on St.Louis had 27 goals, a ridiculous difference of almost 60 (!).
You could also throw in a few lesser points like Hull's not scoring any of his 86 on an empty net (I think Gretz had 4 empty-net goals in 1981-82), and his goal-scoring being more consistent. As I mentioned, above, Hull scored goals (1 or more) in more NHL games during 1990-91 than any player in history ever did, including Gretzky and Lemieux.
My opinion about Gretzky (in his prime) as a goal-scorer is that he mainly scored goals when it suited the play for him to shoot (or to charge the net, though he rarely did that after about 1987/88), but he wasn't bothered with scoring goals unless the play demanded that he do so. He was a playmaking center, who was so good offensively that he led the NHL in goals 5 times and scored more goals in two seasons than any other player ever has. Even during his 92-goal season, he spent about two or three weeks trying to set-up Dave Lumley for goals, and consequently he didn't score for several games (yes, during a 92-goal season he had a goal-scoring 'slump').
Partly as a consequence of this, Gretzky was a more large-volume goal-scorer (in a way, more 'streaky') than Hull was during 1990-91. Gretz might go five or six games without a goal, and then suddenly score 7 in two games. Hull was more consistent in his very best season.
Just my opinion about it. I'm open to other ideas.