Here is the equation
if the favorite team don't cover their point spread + 6 in the first half you bet on the under dog 2nd half. If they cover both point+6 then u pick favorite.
Example from last week NFL
Cin vs Tampa 1st half Cin 10-7 2nd half 11-17
Buf vs Jack 1st half 13-13 2nd half 13-23
Orlean vs Azi 1st half 13-10 2nd half 7-20
SD vs raiders 1st half 12-10 2nd half 10-20
Greenbay vs Was 1st half 10-3 2nd half 3-13
Giant vs Hou 1st half 24-3 2nd half 10-7
I can go on and on but you get the idea. I don't have time to explain in detail but just remember this 80% of the game, the point and total only win 1 way which mean teaser 6 point will not help you win the game....
oh last but not least Jets vs Vik 1st half 9-0 2nd half 20-20 which vik win 2nd half bet (+1/2). Jets was giving 4.5 +6=10.5 and they only win by 9.....
go back as far as you want and check every game and see for yourself. Remember if favorite don't cover their point + 6 they are toast in the 2nd half.
Good luck and start winning.....