Key Numbers

Key numbers are margins of victory that occur disproportionately often in a sport. In the NFL, 3 and 7 are the biggest key numbers — a huge percentage of games end with a margin of exactly 3 or exactly 7 because of how field goals and touchdowns score. Sharp bettors care about key numbers because the half-point on either side of a key number is genuinely worth more than a half-point elsewhere on the spread.

NFL key number frequency

Approximate distribution of NFL final score margins (regular-season games over the past decade):

Margin	Frequency
3	~14–16%
7	~9–10%
6	~5–6%
4	~5–6%
10	~5%
14	~3–4%
1	~3%
17	~3%

Notice: 3 and 7 alone account for nearly a quarter of all games. Compare to a hypothetical even distribution (~3% per margin) and you see why these specific numbers dominate handicap pricing.

Why 3 and 7 matter

• 3 = the value of a field goal. NFL games end on field goals constantly, so the “winning by exactly 3” margin happens when a team kicks a late FG to take a 3-point lead and the opponent doesn’t answer.
• 7 = the value of a touchdown + extra point. Same dynamic — late TDs leave a 7-point gap.

Other key numbers:

• 6 (TD without the XP, or two FGs)
• 4 (FG + a safety, or 4-point swings late)
• 10 (TD + FG)
• 14 (two TDs)

How key numbers affect the spread

A spread of -2.5 is a normal half-point. A spread of -3 (whole) carries push risk because the game can end on a 3-point margin and refund the bet (no win, no loss). A spread of -3.5 crosses 3 — meaning to win the bet at -3.5, you need a margin of 4 or more (since 3 doesn’t beat -3.5). The half-point from -3 to -3.5 isn’t worth what a half-point elsewhere is worth, because it crosses the most common margin.

This is why sharp bettors care about buying half-points across key numbers. Going from -3 to -3.5 typically costs more juice than going from -10 to -10.5, because it’s a more valuable line move.

Buying points

Sportsbooks let you “buy” a half-point at a juice cost. Going from -3 to -2.5 might cost going from -110 vig to -130 vig. Whether that’s a good trade depends on:

• The frequency of the key number you’re crossing
• The size of the juice change

For NFL spreads crossing 3: the math typically says buying off 3 (going from -3 to -2.5) is about break-even at -130 juice. Buying onto 3 (going from -3.5 to -3) creates push risk — it’s not always +EV.

For totals at the 41 / 44 / 51 marks, the same idea applies but key totals are weaker than key margins.

Other sports

Key numbers exist in other sports but are weaker:

• NBA: minor effects around 3, 5, 7 — three-point shots and free throws create some structure but margins spread more uniformly.
• NHL: 1 and 2 dominate — most games are decided by 1 or 2 goals.
• MLB: 1 dominates — half of games are decided by 1 run.
• Soccer: 1 dominates similarly.

For NFL bettors, key numbers are foundational. For other sports, they’re worth knowing but less load-bearing.