I could also change it so no changes after noon, then I could always post both at noon, so you know who to root for and against.
I don't want to do that without that slight rule change though, because say someone picked a noon game and someone picked a 3:30 game. Then the noon pick looks like it's going to lose, so the 3:30 pick changes his to a safer pick that they were otherwise planning on saving, knowing now all they need to do is survive this week to win.