From 2014-15 through 2016-17, Kane was the highest scoring player in the NHL while playing the least amount of games among those top scorers. Only McDavid produced more on a per-game basis (1.17 to 1.15) though McDavid did not play in 2014-15.
Kane was the leading scorer in 2014-15 at the time of his injury. He went on to lead the 2015 playoffs in scoring. He was the leading scorer in 2015-16 by 17 points. He finished 2nd in scoring in 2016-17. As an individual, Kane performed better than Crosby over the totality of the three seasons following Crosby's 2014 Hart Trophy.
I say all of this because if three years of Patrick Kane wasn't enough to supplant Crosby in your mind, then I don't understand how 2006-07 alone is enough to carry Crosby's status through that 2007-08 to 2009-10 period when Alex Ovechkin won three-straight Lindsay/Pearson trophies along with two Harts and a runner-up to Henrik Sedin. Ovechkin was better in the year before Crosby's Hart (Pearson nomination in 2005-06) and better in the three years that followed, so if Kane didn't do it long enough, are you applying this standard equally to Crosby?
With Patrick Kane and Erik Karlsson and Carey Price and Connor McDavid and Jamie Benn (and even Evgeni Malkin) as a collective, there's enough evidence that Sidney Crosby has not been the best player in some time. That no one individual has established himself to be all alone on top for more than 1-2 years at a time does not mean that Crosby has been the best player by virtue of holding that distinction immediately before the recent rotation of Hart/Pearson winners that has not included him. Despite playing reasonably healthy seasons, he hasn't breached the 90-point barrier in 4 years - trailing the Art Ross winner by 21, 11, and as of now 19 points over the last 3 seasons.
If you want to paint with broad strokes until you feel comfortable that McDavid as an individual has the spot, I get it. But then it's only appropriate to say that Crosby's clock as the best didn't really start until 2010ish given how Ovechkin was playing in those early years save for one season of the five where Crosby was better than him.
The best player is intended to be a fluid designation, not simply looking at individual seasons in a vacuum.
If partial seasons and PPG are reasonably considered for Kane, then how isn't Crosby so far ahead of the pack as of 13/14 that it should take more than one season of superior play to join or overtake him? He was as dominant as Jagr was at his peak PPG-wise over a four season period from 10/11 to 13/14.
As of 13/14, Crosby was the best player by a gap not seen since Jagr as of 99/00 (if we are just considering forwards). I don't think there was a clear 2nd best at that point but rather a pack of players such as Malkin, OV, Kane, Stamkos.
In 14/15, Kane was behind Crosby in points and PPG, and should reasonably need to outscore him clearly to make up for the all around game that Crosby brings as a #1C vs. Kane as an offensive winger. Kane was solid in the playoffs again which does earn him some points but OV, Benn, Seguin and Malkin were also in that 2nd group. No player can be said outplayed Crosby that year.
In 15/16, Kane set himself apart from the 2nd group with Benn, and OV to challenge Crosby who was the 2nd best forward, all things considered for the 15/16 season. If Kane had another clear Art Ross win last year or clearly beat Crosby, I would have declared him the best player. Same for OV and Benn.
In 16/17, after a great WC performance, Crosby leads McDavid for most of the season, wins his 2nd Rocket, then wins the Conn Smythe again in a clearer fashion. I think McDavid has earned the 2nd spot over players like Kane, Malkin, Kucherov.
I give other players like Howe, Jagr in 01/02 and OV in 10/11 the benefit of the doubt after a drop in their performance to see if they can get back up the best player level the next season, I think Crosby has earned that for this year given that McDavid has not necessarily Gretzkyed the league.
