It depends on your settings and game tempo.
If you play "fairly fresh" for a starter and "getting tired" for a bench player then the bench player will get slightly more minutes than the starter (at least through 7 games so far). I am doing this because I promised a start to a Freshman, but I would rather play the upperclassman as many minutes as possible.
In games with lower tempo and less plays, the starter gets a few more minutes, while in the up tempo games, the bench guy gets more minutes.
This also depends on the stamina of the guys involved, obviously.