A simple betting strategy in the NFL is the 80-20 rule. When the public loads up on one team, 80% or more of spread bets, take the other side. It’s that easy. We’ve been talking about this system for years, which means oddsmakers and casual bettors have had time to adjust. Does the 80-20 rule still work in the NFL?
Since 2003, betting teams receiving 20% or less of spread bets has gone 113-91-9 (55.4%) ATS. However, the system has not been as profitable as it once was.
- 2003 to 2011: 84-64-8 (56.8%) ATS, +15.57 units
- 2012 to 2017: 29-27 (51.8%) ATS, +0.97 units
It is not enough for contrarian bettors to simply target teams the public is off. A few years ago, our friend David Solar at Sports Insights suggested a few additional filters that could revive the 80-20 rule.
- Underdogs of 7 or more points
- Conference games
The sample size decreases but the win rate improves. Underdogs of 7 or more points in conference games getting 20% or less of spread bets have gone 41-18-2 (69.5%) ATS since 2003. Yet, like with the original 80-20 rule the returns have been flat as of late. Since 2012, this system is 10-9-1 ATS.
So, what do we do? You could add more filters to improve the win rate. If you look at underdogs of 7 or more points in conference games getting 20% or less of spread bets in the 2nd half of the season the system is 29-11-2 (72.5%) ATS. That looks great on paper but Bet Labs will ding your system for overfitting the data (poor predictive value).
Another option is to look at the 80-20 rule from a different perspective. Betting percentages are common knowledge these days. Sports Insights offers a free odds page with public betting percentages from contributing sportsbooks. What casual bettors don’t have access to is the spread dollar percentages on each game.
We started tracking where the money was going in the NFL the last two seasons. Since 2015, teams getting 20% or less of spread dollars are 12-6 (66.7%) ATS, +5.6 units. For comparison, since 2016 teams getting 20% or less of spread tickets went 6-6 ATS. It is an incredibly small sample size but it could be the beginning of a new 80-20 rule. We will continue tracking this system to determine if fading the public based on spread dollars percentages is profitable.
For those wondering, in Week 8 the Jets (+4) and Browns (+9.5) are receiving 20% or less of spread dollars.
NFL Pro Systems
All picks are 44-28 (61%) ATS in 2017