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. All bets below will follow that logic.
Sunday 1PM Slate
Josh Doubs u208.5 passing yards -115 (FanDuel): Doubs is leading a Cardinals offense that is full on tank mode. He's playing behind a dreadful offensive line and is up against the Commanders, who have one of the better defensive lines in football. In these spots, I'd normally prefer over - zig while the public zags - but this line is higher than I'm seeing him projected at.
Brock Purdy u235.5 passing yards -115 (PointBet): Despite being the literal last pick in the draft, Purdy was able to ascend to a starting role. In general, I felt his success was a tad overblown. He played well, but Kyle Shannahan's system has a tendency of making quarterbacks look better than they are. This number is a good 15 yards higher than his projections, as he faces a Steelers defense that bolstered it's secondary by adding veterans Patrick Peterson and Desmond King, as well as drafting Joey Porter Jr.
Brandon Aiyuk u54.5 receiving yards +100 (Caesars): See above on the matchup against the Steelers. Aiyuk is consistently projected below this number.
Anthony Richardson u45.5 rushing yards -110 (DraftKings): Richardson was the 4th overall selection and this years draft. He's produced a blazing 4.43 40 at this years combine and had several 100-plus yard games at Florida. Richardson will have his work cut out for him early, playing behind a poor offensive line and without RB Jonathan Taylor (ankle, PUP) and TE Jelani Woods (hamstring, I.R.). His rushing projections are consistently lower than this.
Chris Godwin o5.5 receptions +124 (DraftKings): I wrote about the Bucs offensive line issues in the preview blog. I'm expecting Mayfield to need to rely on the preferred underneath option in Godwin vs the deep threat in Evans. Given the WR/CB mismatches (also covered in said blog), I'll take Godwin's over with dog odds.
Sunday 4PM Slate
Justin Herbert u294.5 passing yards -110 (Bet365): Herbert has been criticized for dinking and dunking despite his undeniable arm talent. Presumably the issue was the offensive scheme rather than Herbert himself, which is why bringing in Kellen Moore as offensive coordinator makes this such an exciting season for Herbert fan's. As for this game, he's projected well below this number facing an underrated Dolphins defense.
Raheem Mostert u63.5 rushing yards -115 (DraftKings): Mostert will get the bulk of the carries for the Dolphins, but both Salvon Ahmed and rookie De'Von Achane will also contribute. The game environment isn't ideal for running (our model has the Chargers as 2.4 point favorites), and with LT Terron Armstead (leg) likely out, this is a mismatch in the trenches in favor of the Chargers. His projections all reflect that this number is too high.
Sunday Night Football
CeeDee Lamb o6.5 receptions +124 (DraftKings): Lamb will be facing a young and unproven Giants secondary. This is right at his projection, so I'm happy to take the side with dog odds.