I am not sure how one can put Ovechkin outside of top20 all-time, given how close he is to Bobby Hull and Richard, who are certainly top10 and many people have one of them at #5 for different reasons.
Here is the comparison with Bobby Hull I did two weeks ago in another thread:
Bobby Hull is from a six-team all-Canadian league, and Ovechkin is from a 30-team international league. It seems that it is much easier in the former case to accumulate things like top10 finishes and open wide leads over #10, since #10 in a six-team league is just an average first-line player.
The numbers bear it out: in 1944-1970, the average lead of the goal-scoring title winner over #5 was 45%. In 1996-2017, the average lead of the goal-scoring title winner over #10 was 44%, almost exactly the same.
Similarly, an average Art Ross winner of 1944-1970 led #5 in points by 30%, which is exactly by how much an average Art Ross winner led #10 in points in 1996-2017.
So, leads over #5 (and top5 finishes) from 06 era are comparable to leads over #10 from the current era. One can probably even cut modern players a bit more slack when comparing them to 06 stars, since the goal-scoring title in 1944-1970 was won, in 17 out of 26 seasons, by either Richard, or Howe, or Bobby Hull, and in 1997-2017 only Ovechkin is comparable to them. But I am not going to adjust for that.
Bobby Hull's points leads, in %
29-23-19-19-18-3-0
Ovechkin's points leads, in %
29-27-25-14-14-11-0
Suprisingly, Ovechkin comes out with an edge in points.
Bobby Hull's goals leads, in %
86-80-56-54-44-32-30-26-10-9-0
Ovechkin's goals leads, in %
63-61-52-52-50-44-43-30-15-6
Bobby Hull is still ahead, mainly on the strength of his two-year peak. Is this gap in goals enough to compensate for the gap in points? Probably yes. Does it put Bobby Hull far ahead? Probably not. Can Ovechkin catch up? Even a 35% lead over #10 this year will make it closer, 1-2 years like this one, and Ovechkin is at least tied with Bobby Hull.
Here are more things to ponder: if you sum Hart vote shares for the full career, Ovechkin is way ahead of Bobby Hull (397 vs. 294),
http://hfboards.mandatory.com/posts/104180715/
That might be time-specific to an extent, but one also cannot exclude the fact that the difference is due to the fact that Ovechkin has 3 Harts and Hull has 2, and peak Ovechkin was winning his Harts in a more dominant fashion (against peak Malkin and peak Datsyuk, who are a strong competition).
What Hull has over Ovechkin is all-star teams places (10*1st, 2*2nd vs. 7*1st, 4*2nd), but then again, in a six-team league many players would not play first-line minutes and significant PP time, and that would not give them a chance to succeed. E.g., last year Ovechkin was 3rd in all-star team voting behind Marchand and Panarin - would both of them be playing on the first line in a six-team league (especially Panarin)?
So if Ovechkin is so close to Bobby Hull, how can he be out of top20? He must be on the cusp of entering top10.