Crosby seems to be the type of guy who finds a weakness (or better put something he isn't elite at) then will spend an entire off-season perfecting it, then do it with another skill the next year. A lot of this is natural skill, but it isn't at this level without an insane amount of practice. Pretty sure I heard Michael Jordan was very similar and worked to add a new aspect/perfect something each off-season, most notable examples being the post up game he added later in his career, shooting from range, the fadeaway and improved defense. Crosby seems to be motivated in a very similar way. I'm not sure we've had a superstar of this magnitude in the NHL who has put as much work in mastering all aspects of his game.