NFL Key Numbers — Why 3 and 7 Matter
WeBall3 min readUpdated Aug 15, 2026Reviewed Aug 15, 2026
Football does not score in ones. It scores in threes and sevens, and after enough games that arithmetic prints itself onto the distribution of final margins.
The distribution is spiky, not smooth
If margins were smoothly distributed, every half point would be worth the same. They are not remotely smooth.
Across NFL history, roughly 15% of games finish with a three-point margin and around 9% with a seven-point margin. The next most common numbers — 6, 10, 4 — trail well behind, and most other margins sit in the low single digits.
What that does to half points
The value of a half point is simply the probability of the margin it crosses. Moving from −3.5 to −3 converts every three-point loss from a loss into a push, which is worth roughly 15% of your stake in avoided losses. Moving from −5.5 to −5 converts only the five-point margins, worth about 4%.
Pricing a half point around 3
- 01You want to move from −3.5 to −3, which turns three-point losses into pushes.
- 02Three-point margins occur in roughly 15% of games, but only about half of those go against you here — call it 7.5% converted from loss to push.
- 03A push returns your stake, so each converted game is worth the full stake rather than double.
- 04That makes the half point worth roughly 7 to 8 cents of expected value per dollar.
The lesson is not "always buy the half point". It is that a half point around 3 is genuinely valuable and books price that value in — usually generously in their own favour. The cheaper way to get the number is to shop for it.
Where 3 sits changes the bet
A spread of −2.5 and a spread of −3.5 look almost identical and behave very differently. At −2.5 you win every three-point victory; at −3.5 you lose them all. That single point of difference swings something like 15% of outcomes.
This is why line movement across 3 matters so much more than movement elsewhere. A line moving from −2.5 to −3.5 during the week is a far bigger change than one moving from −6.5 to −7.5, even though both moved a point.
Teasers exist because of key numbers
A six-point teaser lets you move spreads six points in your favour across multiple legs, at much worse odds. Most teasers are bad bets. The exception — the "Wong teaser" — is defined entirely by key numbers: taking favourites from −7.5 down to −1.5, or underdogs from +1.5 up to +7.5, so the move crosses both 3 and 7.
Those two crossings are what historically pushed the hit rate above the breakeven the shortened odds require. The edge has narrowed as books adjusted their teaser pricing, but the logic is still the cleanest illustration of why key numbers are worth understanding. Details on the teaser math page.
Other sports, milder versions
Key numbers exist wherever scoring is lumpy, just less dramatically.
- College football has the same 3 and 7 spikes, but flatter, because margins spread across a much wider range.
- Hockey and soccer cluster hard at one goal, which is why the puck line and Asian handicaps are priced the way they are.
- Basketball is close to smooth. Points come in ones, twos and threes at high volume, so no margin dominates and half points are worth roughly the same everywhere.
Common questions
Is it worth buying a half point from 3 to 3.5?
Only at the right price. Crossing 3 is genuinely valuable, but books know that and charge accordingly — often 25 cents or more, versus 10 cents elsewhere. Compare what you are paying to how often a three-point margin actually occurs before assuming the purchase is good.
Do key numbers apply to totals as well as spreads?
Much less. Combined scoring spreads across a far wider range than margin does, so no single total dominates the distribution the way 3 dominates margins. Half points on totals are worth roughly the same wherever they sit.