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How to Get a Statistical Edge When Betting Over/Under (NFL)

by June 17, 2020

Whether you’re new to sports betting or a betting pro, our Sports Betting Strategy and Advice page is for you. You can get started with our 101 section — including 10 Sports Betting Tips for Beginners — or head to more advanced strategy — like Key Numbers When Betting Against the Spread — to learn more.

Whether you like to bet a few bucks on a Sunday to give yourself something to cheer for at the bar, or you like betting on the NFL consistently to make money, someone has probably told you that you’re wasting your money.

They are not technically wrong. If you look at a single bet, it’s impossible to guarantee you’ll make money. Their mistake, however, is massively over-reacting to the inherent uncertainty of playing the odds. Our job, as bettors, isn’t to only pick winners. Instead, it’s to mitigate that uncertainty your more cautious friend so correctly identified.

Indeed, by following a simple set of rules, and by paying attention to a specific set of statistics, you can minimize your risk. They won’t guarantee that you’ll make money, but they may help you start betting with a statistical perspective.

If you want to understand more about what we mean by a “statistical edge”, you can find out more in the sister article to this, How to Get a Statistical Edge When Betting Against the Spread (NFL). Effectively, what we found is that you need to find a way to only make bets that have a greater than 52.3% chance at winning.

To start finding O/U lines that will cover over 52.3% of the time, it’s important to research weekly matchups, but you’ve got to do the right research. Below are the most important statistical categories you should pay attention to.

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Passing Efficiency

We discussed this when looking at ATS as well. The truth is, passing efficiency is the be-all and end-all of NFL statistics. Nothing is as stable, nor as important on a game-by-game basis. It is the most valuable indicator of a good offense. When betting O/U, more than anything else, you need offenses that can move the ball.

When you bet ATS, you can be sure that the team you are backing is trying to win. Conversely for O/U, there are multiple game states in which the result you are hoping for is not in the involved team’s best interest. This means that, rather than looking for a type of team you want to back, you need to find a type of game that has a high probability of covering.

The easiest way to do this is to bet over when both teams are in the league’s top half in passing efficiency. Betting under when both teams carry a low passing efficiency is also a smart play.

Play Speed

This one is relatively simple. Certain teams look to use every second of their play clock before snapping the ball. Others do not. We have all experienced the pain of needing a few more points to be scored in the waning moments of the game while the team with the ball runs. Waits. Runs again. You are forced to watch while the precious few seconds remaining tick off the clock.

Because incomplete passes stop the clock, pass-heavy teams are more likely to excel in this stat. Whether or not they are efficient, pass-heavy teams almost always put up more points. Even if they give the ball away, that will help the game go over (think Jameis Winston and the Buccaneers in 2019).

Below, you can see how often teams ranked from 3-29 in plays per game covered the over last year. The top two and bottom three are, almost by definition, outliers. As such, they weren’t included.

The key takeaway here is that the distribution of quality is by no means linear. You should pay the most attention when teams rank in the top or bottom 10, as this is where the greatest advantage will be seen. Almost all key statistics in the NFL follow this basic rule of thumb.

Defensive Efficiency

Week to week defense is the hardest thing to predict and is heavily influenced by a team’s schedule. As such, it should be the very last thing you look at. However, there are times when defense can be the deciding factor in whether or not to place a bet. For example, betting on the over in games where one or both teams have a “good” (as perceived by the public) defense is often a shrewd move, especially if they have an efficient offense.


The key takeaways from this article are twofold. First, you should weigh a team that excels in any given category far more than an average team. Also, if you can only look at one thing to base your bets on, it should be passing efficiency. A good offense should always trump a good defense when deciding where your money goes.

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Ethan Summers is a featured writer at BettingPros. For more from Ethan, check out his archive and follow him @AllSummersLong_.

Betting 101, How-To, NFL