One of the over-riding themes of the NTID conference so far has been the "X-factor", which isn't physiological (unless you consider brain/personality physical, which you may well do, and I may agree with ... but anyway ..).  I've touched on this myself recently.

I'm still not sure ... The x-factor is best defined as dedication and passion, and much seems to be made of the fact that the most dedicated athletes (and ballet dancers, violinists etc ...) are the ones who reach the elite level.  As a result, there's been a bit of a cultural shift in the talent ID process, they're (we're!) trying to focus on x-factor stuff more.  I agree that it's important and much is made of how much and how well someone trains leading to their elite-level performance.  But is the tail wagging the dog?  I suspect to a certain extent it is.  The kids that naturally do very well (the talented ones!) get positive feedback, so they enjoy their pursuit, they then practice more and smarter, and get better.  But they have to have talent first, I think.  The feedback loop seems to be being forgotten or overlooked in the haste to redefine selection criteria.   Not always is it the most talented physically (sometimes for them it's too easy, which leads itself to complacency or fear of failure), but I suspect that the current emphasis on the X factor may be taking things too far, and most coaches gut feeling would probably reflect this. 

Interesting stuff all the same...