Not directly. There are situations (at every top-notch institution, I think) of sorts that all the candidates are excellent achievers, no matter what measure.

Not directly. There are situations (at every top-notch institution, I think) of sorts that all the candidates are excellent achievers, no matter what measure. Then there is a problem how to differentiate between them further. This is where the concept of "fit" comes in, where the recruiting board tries to enrich the "social experince" of this particular microsociety. For example, thinking is, a group of physics graduate students living in the dorms may enjoy a little improvised cello performance by one of them. This happened to my friend. He had a very strong application but, no doubt equally strong, cellist was choosen. My friend had to work part time for the greatest part of the year to afford undergraduate studies at all and it never occured to him that a cello, or any other extracurricular activity (for which he wouldn't have time anyways) was that important to be a well-rounded physicist.