Way way off subject...Strategy for buying tickets on Stubhub

My wife and I are headed to the Cal-Washington football game tomorrow.  I bought my tickets on Stubhub.  I thought there would be a smaller crowd...The game is during the Giants/Cardinals baseball game, so many in the Bay Area would stay home to watch.  Anyways, for a semi large event, when have you found the best time to buy or sell tickets on Stubhub?  Is it the day of the game...People cancel?  Is it days before?  I know weather plays a role in a lot of events.  Just wondering when people dump their tickets and when people end up buying??  Thoughts?  We know winning teams have a lot to do with a crowd too...Thanks, Brian