How to Bet Over Under (And Win)

Sports Betting Odds Board - Dollar Bills

One of the most interesting bets offered by sportsbooks is the over-under bet. I thought it would be fun to write a post that was basically the biggest, most complete guide to how to bet over-under. I also thought it would be fun to include advice about how to win money placing these kinds of bets (which are also called “totals.”)

The over/under bet is available in multiple sports, so I’ll cover some of the specifics related to specific sports in this post, too.

What Is an Over Under Bet and How Does It Work?

An over/under is a bet on the sum of the scores of 2 teams in a game. The sportsbook sets it at a certain value, and then you bet on whether the actual total score will be higher or lower than that prediction.

Here’s an example:

You might have a football game where the over/under is 43. Team A scores 14 points, and team B scores 21 points. The total of those 2 scores is 35, which means a bet on the under would have won. A bet on the over would have lost.

If one team had scored 27 points, and the other, 21 points, the total score would have been 48. In that case, a bet on over would have won and a bet on under would have lost.

Most books like to have an equal amount of action on either side of a bet. That way they’re guaranteed a profit, because they make you risk $110 to win $100. If they have equal amounts of action on both sides, the losers pay off the winners, and the book gets to keep those extra $10 that were risked by the losers.

They try to set the value for the over/under based on a 50/50 probability of winning. The oddsmakers at the books determine this point value based on the statistics available for the games, including the strength of the teams, their win-loss records, and how many points each team tends to average per game—especially against teams of similar strength.

They also account for things like weather, who’s playing at home, who’s playing away, who’s been injured, and so forth.

Your goal, as a sports bettor, of course, is to win more than 50% of the time. After all, if you only win 50% of the time, you’ll lose money because of the vig.

What Is the Vig and How Does It Affect Over Under Bettors?

The “vig” is short for “vigorish,” which is the mechanism that the book uses to make a profit off their business. At most books, you have to risk $110 to win $100 on a 50/50 bet. That extra $10 is the vig.

At some books, on some bets, you might be able to pay a reduced vig. You might only have to risk $105 to win $100.

At other books, on other bets, you might have to pay a higher vig. You might have to risk $120 to win $100.

These bets are listed at the books as follows:

  • -105
  • -110
  • -120

I should point out that this doesn’t mean you must place a bet of $100. This number just represents the ratio of winnings to losses, using $100 as an example.

You could place a -110 bet for $50, for example. In that case, you’d risk $55 to win $50. You could bet $22 to win $20, too. Most books have a minimum bet, but as far as I know, no books have a minimum bet of $100.

The implications for your bankroll and your winning percentage should be clear, but let’s take a look at it statistically:

Let’s start with my friend Bryan. He literally wins 50% of his bet, and he loses 50% of his bets. Let’s assume he places 100 bets for $100 each, and he wins half of them, losing the other half. And he’s betting with the standard vig, where he’s risking $110 to win $100.

He’s lost $5500, but he’s won $5000. His net loss is $500 on those 100 bets, which is $5 per bet. That’s a negative return on investment of 5%.

Now let’s look at my friend William. He’s smart. He only bets on what he thinks are “sure things.” Of course, there’s no such thing as a sure thing in sports betting, but he still wins 55% of the time.

This means over 100 bets, he loses 45 bets at $110 each, for a total loss of $4950. He wins $5500, so his net win is $550. That’s a positive return on investment (ROI) of 5.5%.

The Rule of 72 can be used to determine how long it will take to double your money. It suggests that you divide your return on investment by 72 to determine how long it takes to double your money.

If you’re re-investing all your profits every week and seeing a 5.5% return on your investment, you should be doubling your money every 13 weeks.

This might not sound that impressive, but consider this:

  • Most people would be thrilled to see a return of 20% on their money over the course of an entire year.
  • A 100% return every quarter is stellar performance compared to that.
  • A 55% win ratio doesn’t sound that impressive, but that’s close to the best that a professional sports bettor can count on over the long run.

Sure, you’ll find plenty of websites with experts claiming a 65% or 70% win ratio, but they’re usually looking at a small sample size. Or they might be flat-out lying, too. After all, they’re in the business of selling picks.

I submit that if you could pick winners 60% of the time, you wouldn’t sell your picks. You’d just put as much of your own money into action as you possibly could every week.

That might make it sound easy.

It’s not.

Beating the spread, or getting a better than 50% win ratio against the book betting on the over/under, requires a herculean effort and dedication the likes of which most casual sports bettors will never have.

How a Push Works, and How Some Books Avoid Them

A “push” in gambling is a tie result. The bettor doesn’t win any money, and the book doesn’t lose any money. The bettor just gets his original bet back with no winnings.

In the example above, where the over/under was set at 43, you might have a final score of 29 to 14. The combined score is 43. In that case, a bet on the over and a bet on the under would both be pushes, because the total was the same as what the book had predicted.

If I were running a sportsbook, I wouldn’t want to spend a lot of time managing bets that might result in a push. It’s a lot of work for no reward.

A lot of books agree with me, because they often set the total as a number with a 0.5 at the end of it.

If the over/under on the game were 43.5, then a score of 43 would win if you’d bet the under. A score of 44 would win if you’d bet the over. There’s no opportunity for a push, because a game can’t end with a fractional score ending in 0.5.

This means that half are going to win, and half are going to lose, assuming an equal amount of action on either side of the bet.

How to Improve Your Win Ratio When Betting the Over Under

Most of my readers are going to be interested in betting the over/under on NFL football games, so I’ll offer some advice on how to improve your win ratio when betting the over/under in the NFL. Much of this advice can be extrapolated to other sports, like the NBA, although you might need to make some adjustments to your thought processes based on the nature of those other games.

One thing to keep in mind is that sports fans love high-scoring games. You’ll see plenty of them bet on the over leading up to the actual game, and the book will move the over/under to compensate for the lopsided action.

This means you have 2 opportunities and/or considerations:

The first is that if you like the over on a game, you should probably bet on it early in the week before the money starts coming in on it. The closer you get to kickoff, the better your probability of winning an under bet becomes—because of the line movement.

And that’s the 2nd thing—the most effective strategy for betting over-under is to watch for the line to move. Bet accordingly.

Generally, it’s best to bet against the public. Fading the public has always been an effective sports betting strategy, and it probably always will be.

Bankroll management:

Is also important to sports bettors who like over/under bets. Anything can happen on any given Sunday. You can have a 60% chance of a 70% chance of winning a particular bet, but that doesn’t mean you WILL win that bet.

The more of your bankroll you’ve risked on that bet, the better the probability of your going broke.

And that’s something you don’t need.

I suggest limiting the size of any over/under bet to 1% of your total bankroll, no matter how confident you are. If you absolutely MUST be aggressive, NEVER go over 5% of your total bankroll on a single bet.

But 1% is better.

Past Statistics Related to Game Totals

When you’re talking about the NFL, you’re talking about a lot of past data. There are over 7500 NFL games already in the books from the last 15 years, and those scores are written in ink. That’s a lot of data to draw some conclusions from.

Also, you probably don’t want to look much further into the past at these statistics. That’s because the nature of the game itself has changed over the last couple of decades. Still, 7500 games is plenty to draw some broad conclusions from.

For one thing, we know that oddsmakers set a minimum over/under of 30 and a maximum over/under of 60.

What conclusion can you draw from that?

The closer you get to one of those 2 extremes, the more extreme the line is. Those games are outliers. Does this mean the lines are more likely to be wrong?

Probably not.

But they probably are the games that are most likely to see big movements in the line. This means these can be the games to watch for opportunities to bet against the public.

You should also keep in mind that just because a trend exists in the past, that doesn’t mean it’s predictive.

For example:

You might look closely at how many games go under or over in divisional games. You might find that a larger percentage of these go under instead of over, and you might assume that this means you can achieve a similar winning percentage by just betting the under on all divisional games.

For one thing, the oddsmakers watch these patterns, too. If they find a statistic that can help them get a closer to 50/50 probability, they’re going to use it.

For another, just because something happened that way in the past doesn’t mean it will happen that way this week or next week. You have an entirely new set of teams and players than you had 15 years ago.

And finally, for the most part, no matter how you slice and dice the data, most of the time, the over wins 50% of the time, and the under wins the other 50% of the time.

If you really want to find value, you’re only able to do that if you combine multiple factors. This includes multiple historical data points along with an analysis of specific game factors.

If you’re looking for a simple system for winning over/under bets, you won’t find it.

Even if you did, it wouldn’t work for long, anyway.

If you really want to make money in the long run from over/under betting, you need to approach it with a long-term perspective. This means sticking with high-value bets and ignoring hunches. It means not risking too much of your bankroll on any single bet.


Placing an over-under bet is easy once you understand what an over under bet is. Winning these bets consistently is another matter entirely.

The sports betting sites are good at setting the lines for over under bets in such a way that you have an almost exactly 50/50 chance of winning, regardless of which side you take.

Just to break even, you need to win 52% or 53% of these bets. To see a strong positive ROI, you need to win around 55% of these bets.

That’s more complicated than you think, too—but it can be done.

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