The most efficient market
NFL spreads and totals are arguably the most heavily traded prices in U.S. sports. That efficiency makes raw 'gut' edges rare; structural ones - situational spots, weather, injury timing, and specific market biases - are where the public bettor can still find value.
Variance is enormous
A 17-game NFL season is a tiny sample. A 55% bettor will still have multiple losing weeks per year. Bankroll discipline matters more here than in higher-volume sports.