NFL Kelly Criterion Betting
NFL Kelly criterion betting is how you turn an edge into a sustainable bankroll plan. It tells you exactly how much of your bankroll to risk on each NFL bet based on your edge — and how to avoid going broke during the inevitable cold streak.
The formula in plain English
Kelly says: bet a percentage of your bankroll equal to (edge ÷ odds). A +5% edge on a +100 bet means risking 5% of your roll. A +5% edge on a −200 bet means risking 10%.
Why nobody actually bets full Kelly
Full Kelly assumes you know your true win probability. Real NFL edges are noisy — you think it's +5% but it might be +2% or −1%. Overestimate your edge and full Kelly will blow up your bankroll. Quarter Kelly survives the noise.
Workflow
Find a bet with real edge using the NFL EV calculator. Convert prices with the NFL odds calculator. Apply quarter Kelly. Move on to the next one. Trust the math, not the streak.
Frequently asked questions
What is the Kelly criterion in NFL betting?
The Kelly criterion is a formula that calculates the optimal bet size as a percentage of your bankroll, based on the edge and odds of the bet. It maximizes long-term bankroll growth while avoiding ruin — and it's only useful on bets that already grade as +EV in the NFL EV calculator.
What's the Kelly formula for NFL bets?
Kelly % = (bp − q) / b, where b = decimal odds − 1, p = true win probability, q = 1 − p. For +150 odds with a 45% true win rate: (1.5 × 0.45 − 0.55) / 1.5 = 8.3% of bankroll. Convert American to decimal with the NFL odds calculator, and devig the price using the implied probability calculator.
Should I use full Kelly on NFL bets?
Almost never. Full Kelly assumes you know your true win probability exactly — and you don't. Most pros use quarter Kelly or half Kelly to survive variance, especially given that AI NFL prediction accuracy caps out around 55% ATS.
What's quarter Kelly?
25% of what the full Kelly formula says to bet. It gives up some growth in exchange for dramatically smaller drawdowns. For most NFL bettors, this is the right setting.
Does Kelly work on NFL parlays?
Technically yes, but the variance is brutal. If you must Kelly a parlay, use a tiny fraction (1/8 Kelly) and accept that variance will be much higher than on straight bets. Grade each leg's EV separately first in the NFL EV calculator.
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