The bets are determined by checking a wide variety of projections against my own knowledge of how players will be utilized given game context. The player prop lines were taken from this site.
When analyzing projections from fantasy sites, you'll often find that the projections are higher than betting lines, which will make you bet shit tons of overs. This is a common mistake. The projections are mean based, which tend to skew higher because the range of outcomes are not evenly distributed. (i.e., a running back on a good day could go for over 100 yards, but he would never go under 0... hopefully). If you find a mean projection lower than the Vegas line, the under is likely a good bet. To bet an over, the mean projection should be significantly higher.
Sunday 1PM Slate
Marcus Mariota o159.5 passing yards -128 (FanDuel): Mariota is going up against a Panthers defense that ranks 22nd in pass defense DVOA. He's also consistently projected much higher than this number. He's gone under this number in his last 4 games, which is a potential explanation as to why it's this low.
PJ Walker o184.5 passing yards -115 (BetMGM): We're again on Walker's over, who is up against a Falcons defense that ranks dead last in pass defense DVOA. Projections have him consistently well over 200 yards.
Justin Jefferson o7.5 receptions +115 (BetMGM): This is a big number, but Jefferson is going up against a bad Cardinals secondary (27th in pass defense DVOA). The projections match this number, so I'm happy to take the dog odds.
DeAndre Hopkins o6.5 receptions +114 (Caesars): Hopkins returned from suspension and immediately returned to his role as the Cardinals WR1, which was badly needed after Marquise Brown went down (rhyme unintentional). The Cardinals are 3.5 point dogs to the Vikings, who does have a decent secondary -- but since our model prefers the Vikings with 3.5 points, we expect Arizona to need to throw plenty.
Caleb Huntley u40.5 rushing yards -120 (PointBet): With Cordarrelle Patterson still out, Huntley runs behind Tyler Allgeier in the Falcons backfield. Up against an underrated Panthers defensive line, Huntley is consistently projected below this number.
Sunday 4PM Slate
Malik Willis o152.5 passing yards -117 (Caeasars): Regular readers of this site know that it's not uncommon for me to take a backup QBs over. It's not that I specifically target that scenario, but it does seem that the public underestimates how important volume is when it comes to cumulative statistics like passing yardage. Willis is up against a Texans defense that ranks 24th in pass defense DVOA. His projections are consistently in the 180s. Willis's passing game may be a bit raw, but he led all of college football in "big time throw" rate last season. The big play potential is certainly there.
Darrel Henderson o35.5 rushing yards +100 (PointBet): Henderson should get the bulk of the Ram's carries with Cam Akers (personal) out. This number is certainly too low, but the fact that we're getting it at even money is a big reason why I'm taking this bet.
Chris Moore u32.5 receiving yards -110 (BetMGM): Collins works as the Texans slot receiver and is consistently projected below this number.
Sunday Night Football
Sammy Watkins u3.5 receptions +120 (BetMGM): Even though Allen Lazard is out and the Packers are double digit dogs to the Bills, this number matches projections. I'll take the dog odds on either side. Despite consistent injuries to the Bills secondary, they continue to be one of the stingiest pass defenses in the NFL.
Monday Night Football
Hayden Hurst u38.5 receiving yards -113 (Caesars): With Ja'Marr Chase out, Hurst will have an expanded role in the Bengals pass catching game. That said, the Browns have done a good job against tight ends this season (albeit against not so strong competition), ranking 12th in DVOA against the position. Given that their pass defense is 28th in DVOA, covering tight ends is the one thing that they aren't horrible at.