The Effects of Travel, Time Zones, and Game Start Times on Team Performance in the National Football League

This study examines whether travel distance, time zone changes, travel direction, and game start times affect team performance in the modern National Football League (NFL). Earlier research suggested that eastward travel and circadian misalignment create measurable disadvantages, particularly in early games. Using game-level data from the 2015-2025 seasons, this analysis estimates fixed-effects regression models that control for team strength using ESPN's Football Power Index (FPI) differential and include interactions between time zones crossed, travel direction, and start time. The results provide limited evidence that travel systematically reduces performance once team strength is accounted for. Across linear probability, ordinary least squares, and a logistic model, FPI differential emerges as the dominant predictor of both win probability and point differential. Travel distance, time zones crossed, and eastward travel are generally small in magnitude and statistically insignificant. Interaction terms designed to test for the circadian misalignment effects across start times also fail to give robust evidence of a consistent eastward disadvantage. Overall, the findings suggest that, in the modern NFL, matchup quality plays a much larger role in determining outcomes than geography or scheduling structure. While biological theory predicts disadvantages associated with eastward travel and early starts, these effects do not appear consistently in recent data once team strength is controlled for.