every year for the last 5 i have made a big bet 2-4 thousand on under on a nfl team.i am 4-1 with the loser nyj geno smith rookie year.anyway last year i took under 7 for chi bears at -150.there was a bunch of 6and half at -110 out there.so why take 7 and lay extra juice? it is because for you to lose you would need the bears to actually win eight games so it gives you a buffer.to win you still need 6 or less but if you are wrong or they win a fluke game ie at kc and it hits 7 you would push and get your money back instead of losing your big bet.if you win you will still be happy with the cashing of the ticket even if it is a little less.