For myself if it's raining i take the under most of the time, although CedarCreaker you make valid points on defender/receiver coverage. I figure if it's raining then you will most likely run the ball, take time of the clock because you don't want to throw a wet ball not as accurate. The receivers probably would have more dropped balls because it's hard to catch a dry ball let alone a wet one. When the field is wet you don't get a lot of big plays broken from the line of scrimmage and receivers have a hard time making their cuts and moves. I liked the under regardless of the conditions. Good luck with what ever you play on.
