Its the amount of money placed on each team. If $5mil is wagered on the Baltimore this Monday and only $1mil on Saints then saints easily win. But that information isnt given out. And with all those futures bet on Saints over 9.5 wins and SB odds, I dont think Vegas pays those out.
Now if we beat Baltimore, Pittsburgh is on a bye. Our win will be fresh in everybodys minds. They get 2 weeks to prepare for us. If I had to place a wager on that game right now, I would put my money on Pittsburgh and not be hesitant. Pittsburgh always gives us problems.