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.
Pat Mahomes u310.5 passing yards -114 (FanDuel)
Jerick McKinnon u25.5 rushing yards -108 (Caesars)
Kadarius Toney u32.5 receiving yards -115 (Caesars)
Trevor Lawrence u250.5 passing yards -114 (FanDuel)
Travis Etienne u71.5 rushing yards -101 (Caesars)
Travis Etienne u2.5 receptions +115 (BetMGM)
Daniel Jones u45.5 rushing yards -120 (PointBet)
Josh Allen u50.5 rushing yards -120 (PointBet)
Stef Diggs o6.5 receptions +110 (BetMGM)
Ja'Marr Chase o7.5 receptions +106 (FanDuel)
Hayden Hurst u33.5 receiving yards -115 (BetMGM)
George Kittle u3.5 receptions +130 (DraftKings)