Hope it's alright if I go ahead and make this thread, but I agree with others that it's not fair to clutter up prospect-specific threads with this kind of talk.
In short, I disagree with a "meat and potatoes" philosophy.
Always take the best player, not the most physical one ranked within whatever range you're picking in.
Thanks for opening the thread for this particular type of prospect 'discussion'. I don't mind these debates, just nice not to have to wade through the Virtanen thread to find stuff specifically about the player.
Anyway you and Uhmkay were debating the impact of size on player's projections and/or likelihood to reach the NHL. You both give numerous 'spot' examples which, at the end of the day, don't amount to much since it is unknown how representative they are of all junior and NHL players. And we obviously know both sides hand pick the examples that suit their argument.
So I thought I'd take a stab at quantifying how much size drive's a players' chances of success at the NHL level. Keep in mind this is just a toe in the water as I haven't really wrapped my head around the 'best' way to represent the numbers. Nor is my sample terribly large since I have to manually look up the height of each player in the analysis (nothing is listed in row format). And of course this is all at the mercy of the biases and inaccuracies of the sources I've used (WHL, OHL, and QMJHL sites for juniors, NHL.com for NHLers).
Basically my thinking is if Height is no source of advantage or disadvantage in the NHL, I would expect the ratio of player heights in the NHL to be roughly similar to the ratio of player heights in the CHL. Pretty simple idea. For example, if 20% of CHL players are under 6 feet and 20% of NHL players are under 6 feet, then there is no clear bias towards or away from players under 6 feet. If the ratio of players is higher in the NHL then it would seem there is a premium on being sub-6 feet. If the ratio is lower in the NHL then it would suggest there is a premium on being over-6 feet.
For sample, I took the top 20 scoring forwards in each of the WHL, OHL, and QMJHL to give me a total of 60 CHL forwards. I took their heights only because height tends to stay the same from junior to NHL while weight tends to increase with age and training. I also took the top 30 scoring forwards in the NHL and their heights. In both cases I used 2013-14 data since I figure the scoring leaders would be more stable at that point.
Here's what I got:
So basically junior hockey has nearly 2x the ratio of sub-6 foot players that comprise the top scorers than the NHL does (43% vs 23%). Even with reasonably small sample sizes (n.60 and n.30) this is statistically significant and on the surface says that the NHL definitely puts a premium on size (in this case height) with sub-6 foot scorers in the CHL is much more common (nearly 2x) than sub-6 foot scorers in the NHL.
What does this mean? Well it certainly doesn't mean that a sub-6 foot player like Ehlers (who at 5'11 is just on the cusp of the sub-6 foot group) isn't going to succeed at the next level, nor does it mean that an over-6 foot player like Virtanen is going to succeed. In fact Virtanen and Ehlers are probably cases to attempt to make this argument for, given their proximity to the 6 ft cut point. But when we look at probability and likelihood to succeed, I don't think there should be any argument that the long run odds do favour bigger players. And even though you can always find a Giroux, Crosby, or Kane that makes it through, there is additional adversity working against them that likely needs to be taken into consideration.
Of course all this obviously doesn't take into consideration the role of weight and strength (similar but not exactly the same), which I can't factor in because I'd have to see how junior weights translate to NHL weights after time for growth and training. But intuitively it seems that weight and strength are more important than height (and that height is probably just a proxy for strength and weight in general) as I only found 5 NHLers in 30 with weights listed below 190 lbs (Giroux, St. Louis, Kane, Krejci, and Eberle) and just 2 listed below 180 (Giroux and Kane). At 176 lbs today, Ehlers biggest challenge will either be to try to reach 190 and at least join a moderate number of small players that have shown they can play under 200 lbs, or take his chances by being only the 3rd player on this list to play below 180.
Nothing definitive but hopefully this helps advance the conversation a bit more.