I only back tested through 2009. Simple system. Bet the opposite of week 1 O/U result for each team using up to a 6 game chase. Example: If New Orleans goes Over in week 1, start a chase on the Under. Each team was undefeated for the last 4 years including 2012. Also, very few chases went beyond 2 games. (Count a push as a no game)
Results:
1 gm - 62 wins
2 gm - 49 wins (that's 111 out of 128 in 2 weeks!)
3 gm - 8 wins
4 gm - 6 wins
5 gm - 2 wins
6 gm - 1 win (only 3 chases of 5 or 6 games in 4 years)
Nothing wrong with starting the first few weeks of the NFL season up 32 wins with low juice.