Excerpt from row2k.com 

Boat lineup are as much art as science. If you had a nickel for every rower who thought they should have been rowing some other seat, you could build your own boathouse. This column attempts to ward off some of the unhappiness and to explain -- in an all-too-brief nutshell -- some of the considerations which go into making up lineups and the reasons rowers may find themselves in a seat other than the one they were sure they'd earned.