Malcolm Gladwell gives a fascinating talk about recruiting here. He claims is that the things we try to have as objective measures to predict future performance often don't work.
This resonated with me, because I am our graduate program coordinator. And we have just the kind of objective measures that Gladwell talks about, mostly undergraduate GPA and the GRE. It's tough, because these are known to be imperfect measures. I've seen students with low undergrad GPAs do fine in grad school, for instance. And there has been a lot of discussion about biases in the GRE, how good the predictive power is, and so on.
I don't think Gladwell is seriously advocating a strategy of, "Let everyone have a go and see who rises to the top." But given that resources are finite, what alternatives do we have? Companies can't hire all applicants, programs can't take all comers, and sports teams can't have infinite numbers of rookies. Gladwell's talk is good at identifying the problem of recruitment, but I am left wanting a hint of a solution.
Still, his talk is good in that it is a healthy reminder of just how imperfect these "objective" measures are.
Speaking of graduate school, grad students may be interested in a networking website called Graduate Junction.