Professional bettors don't bet teams — they bet numbers. Successful sports bettors don't care which team is attracting their action as long as the available line is offering value.
Because of the rules of NFL scoring (field goals, touchdowns, extra points, etc.), points are scored in various multiples, making some margins of victory much more common than others.
For example, since the start of the 2003 season, 15% of all NFL games have finished with a margin of three points. This makes sense because of the frequency of field goals.
Because three-point games are so common, so are games with point spreads on or close to three points. As a result, getting off three (+3.5 for underdogs and -2.5 for favorites) is crucial when attempting to maximize NFL betting value.
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Using our NFL betting archive in Bet Labs, we compiled the most (and least) frequent margins of victory since 2003. Here are the results for all games up to those with margins of 21 points:
While the overall numbers above provide interesting information, it's even more important to analyze key NFL numbers before and after the league moved extra points back to the 15-yard line following the 2014 season.
In the three years leading up to the rule change, NFL kickers made a whopping 99.5% of extra-point attempts. In the three years following the move, made PATs dropped to 93.9%.
Making PAT attempts longer obviously resulted in more missed kicks, but that also has had an effect on margins of victory. The chart below breaks down the biggest differences in margins of victory from before and after the extra point rule change went into effect.
With extra points kicked from the 2-yard line, 5.53% of all NFL games finished with a margin of six points. However, since the rule change, that number has increased to 8.09%. This makes sense with longer kicks; more are missed, with teams having to settle for only six points after scoring touchdowns more than before the change.
The next biggest differences are five points (2.87% to 5.06%), 10 points (6.12% to 4.68%) and four points (5.37% to 4.30%).
For those interested in digging more deeply, here's a full rundown of how key numbers have evolved since the rule change.
As bettors, it's extremely important to understand the evolution of how rule changes affect scoring in the NFL and, in turn, the changing value of point spreads.
Armed with this data, successful sports bettors are better equipped to properly evaluate potential wagers and shop for the best line to maximize betting value.