Mm. Perhaps you are right and I over-stated it as Gretzky "destroying" Bossy, but I was thinking of them overall -- i.e., not only in playoffs, but regular season (and playoffs). I mean, Bossy looks close in overall League rankings (1st, 2nd, etc.), but what about in raw numbers (since we're talking about the same seasons)?
In the same 8 regular seasons that their careers overlap, Gretzky scores nearly 91 more goals than Bossy, an average of 11 or 12 more goals per season. In goals-per-game, Gretzky is also ahead 0.86 to 0.75.
It's fair to say this slightly disadvantages Bossy, since I'm overlooking his 1978-79 (the year before Gretzky was in the NHL). So, to make it more fair, we could look at Bossy's 10 seasons and Gretzky's first 10 (i.e., all of Edmonton plus first-year in L.A.). Gretzky scores 637 goals and Bossy 573.
Gretzky is at 0.82 goals per game, and Bossy at (his career mark of) 0.76.
I mean I love Bossy as much as anyone, but when one guy is primarily focused on playmaking yet scores a dozen goals a year more than another guy who isn't, how is the latter guy the better goal-scorer?
You make a great point, however, about Bossy's playoff goal-scoring (which was superb) being slightly ahead of Gretzky's pace over a certain period of time. But let's break it down:
Overall, Gretzky scored 122 playoff goals in 208 games (0.59 GPG).
Overall, Bossy scored 85 playoff goals in 129 games (0.66 GPG).
Not surprisingly, the raw per-game totals favor Bossy (though not by that much!).
But Bossy, as we all know, didn't appear in the playoffs at all after age 30. If we compare them up to that age, it goes:
Gretzky -- 93 goals in 150 games (0.62 GPG)
Bossy -- 85 goals in 129 games (0.66 GPG)
Wayne is now very close, but still a slight 'win' for Bossy.
But here are my two issues with calling Bossy the greatest playoff goal-scorer:
1) Most of his elite rep here rests on 1981, 1982, 1983. Obviously those were all amazing performances and full marks to him, but three years only to perform as the greatest ever...? If you remove those three consecutive springs, his playoff totals suddenly become 34 career goals in 73 career games, or 0.47 GPG. That's still pretty impressive for playoffs, but it's a long way down from those three peak years.
By contrast, with Gretzky, if we remove his three biggest playoffs in terms of goals-per-game (1983, 1985, 1986), he still has 85 playoff goals in 164 games, for 0.52 GPG. Also down, but not as severely. To put it another way, Gretzky scored 12+ playoff goals five times, Bossy three times. Or, we could also say Gretzky scored 15+ playoff goals over an 11-season span, Bossy a three-season span.
2) Bossy scored 85 playoff goals in 129 games (0.66 GPG), while Maurice Richard -- up to age 36 (still 6 years older than Bossy's eldest playoff) -- scored 81 in 121 games (0.67 GPG) when goals were a lot harder to come by.