I think it's an overall good strategy, but with a few caveats. First, there are always a few top 25 teams that really are dominant- think Florida St. last year, Oregon, Alabama the last few years, etc. If you blindly bet against those type of teams, you'll get burned. What I try to look for is top 25 teams that have overinflated spreads or have a long standing reputation as a program, but are overrated now. Nebraska was a good example the last few years. They supposedly could dominate teams with their run game, home crowd and big, strong linemen. But they are not recruiting like they used to and their time has come and gone. Only since last year had the spreads adjusted.