Are NFL Second-Half Trends Real?
No. A team's tendency to play better or worse after halftime does not repeat: odd vs even games correlate at −0.01, and the first six games vs the rest at 0.04.
Findings
- Second-half point differential carries over a little (0.23), but only because good teams win both halves.
- Once you know a team's full-game point differential, its second-half differential adds nothing.
- Fourth-quarter edges and quarter-by-quarter player splits behave the same way; see the season board for the league-wide 4th quarter table.
More research
Projections are research, not betting advice. Sports betting is not legal in every state. If gambling stops being fun, call or text 1-800-GAMBLER.