Vegas odds have nothing to do with the nmedia or even how good or bad Vegas thinks a particular team will be. The only thing Vegas is trying to accomplish when they set their odds is to get the same amount of money bet on every team.
Since teams like the 49ers, Cowboys, and Giants draw a lot of money no matter what, Vegas will inflate them to discourage money from going to them and then teams like the Jags will be deflated for the opposite reason.
As an example, suppose Vegas thinks the 49ers and the Jags will both finish 8-8 in 2021. They might post the over/under for the 49ers at 9.5 and the O/U for the Jags at 6.5 if that's what they think they need to do to get the money to fall right.
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