Interestingly enough, I have been trying to convince my kid to grow out his hair to improve his game.
I have done a bit of research in this area as to how it potentially relates to human accomplishment and extra-sensory perception.
A little known fact is that American Indians were employed by the U.S. government during WWII as trackers, but they were required to get the standard issue cut.
Their performance in the field was not as expected, they did not preform any better than the typical Americans.
Yet, when allowed to keep their traditional long hair, they claimed it helped them perceive the signals better. . . .
And once the Army let them keep their traditional cuts, they preformed as the Army expected them too. Mojo, or Mental?
So it goes.
I do not, however, have the stats on whether more hair makes a player perform better or not. It would be hard to run a double blind on that. We can only guess if Jordan would have played better with a beard, or if Harden play would suffer should he shave his. . . .
But I am guessing some of the reason these beards are here, is not just fashion. Sports, if you ask these players, is a VERY superstitions and luck oriented thing. If they think it has to do with their success? It isn't going anywhere for now.
Otherwise, who would want to pitch in the summer heat with something like that? Yikes.