I saw the odds last night: 

Current Heisman odds, per Caesars:
QB Bryce Young (Alabama) +180
QB C.J. Stroud (Ohio State) +280
RB Kenneth Walker III (Michigan State) +280
QB Matt Corral (Ole Miss) +700
QB Kenny Pickett (Pitt) +2,500
QB Caleb Williams (Oklahoma) +4,000
RB TreVeyon Henderson (Ohio State) +4,000
QB Sam Hartman (Wake Forest) +5,000
QB Desmond Ridder (Cincinnati) +6,000
DL Jordan Davis (Georgia) +8,000
LB Will Anderson Jr. (Alabama) +8,000

OK, so logically, Stroud is the frontrunner to win the Heisman.

1) There's no reason Ohio State should lose to either Michigan St, Michigan, or anyone in the B1G Championship game.  And even if he only has 2 good games passing, winnning all 3 will put him as a Top 3 team in the nation with crazy stats

2) Bryce Young is likely losing to Georgia, but not only losing, having a really bad game on national TV.  That'll set him back.  Admittedly, if he beats Georgia, he wins the Heisman.  That's a much tougher task than what Stroud has.

3) Walker has to beat Ohio State, and have a huge game in the process.  Because both of the above scenarios would have to happen in the negative for him to move ahead.

4) No one else really has a chance except for maybe TreyVeon Henderson, who would have to have 2-3 massive games, and then he could jump the field.

But that said, and I'm not a gambler, if you're laying money right now you have to lay it on Stroud.  It's weird but he's probably going to win the Heisman.