Of the 2 that didn't, the BUF/PHI game was 1 point from a push and HOU/OAK was 3.5 points off.
Do you see this trend continuing throughout the year? Is it due to the shortened off season causing a lack of defensive cohesion, and offenses needing less time to gain sync? If Vegas begins to adjust to this trend, there may be a string of unders around mid season as teams begin to gel defensively.
I can't remember there ever being a season in which defense was so weak, league wide. It's really a weird season in so many ways.