Can You Explain the Plus-Minus System in Sports Betting?

When I show non-gaming friends Vegas odds, they're very confused by the plus and minus system. They want the old-fashioned “3-1/2-to-1” kind of odds. Is there a simple explanation of the plus-minus system or perhaps a real simple method to convert them to something that they can understand? Did Vegas ever use the “7-to-2” type of odds, if so, why did they convert?

[Editor's Note: This question is answered by Blair Rodman, author of our upcoming book All About Sports Betting.]

The way odds are presented at sports books differs in different parts of the world.

In Europe, Australia, New Zealand, Canada, and a few other countries, “decimal odds” are favored. This method includes the original bet in the odds; i.e., a 4-1 underdog would be listed as 5.00, while a 4-1 favorite would be 1.25. No thanks! Too confusing.

In the UK and Ireland, bookmakers favor expressing odds in fractions, known as “fractional odds.” This works well on horse-racing tote boards, as the pari-mutuel odds on the board aren’t meant to be exact and are constantly changing depending on bettors. A horse listed as 3/1 could actually be 2.95-1 or 3.05-1 at the time a bettor plunks down his money. This method is used at American tracks also. Horse bettors understand this and that exact payoffs aren’t known until the results are posted. However, when the prices of the winning horses are revealed, they're in decimal form, with the original bet included in the listed payoff. A winning price on a standard W/P/S bet of $8.60 is based on a $2 bet and the $2 is included in the payoff price, so that bettor would get his $2 back plus a profit of $6.60. (Some exotic bets now use $1 as a base bet.)

In sports betting, fractional odds are, at least to me, more difficult to understand at a glance. Instead of a money line listed as -150/+130, (known as “money-line odds”) it would be 7½-6½. I don’t know why UK books persist in using this clunky method instead of the simpler method developed in America. Maybe they still hold a grudge.

In the U.S., fractional odds are used by some books in bets like futures, where a 30-1 shot might be listed that way. Interestingly, British bookmaker William Hill uses money-line odds, at least for their American customers. (Don’t tell the Queen.) I don’t know if fractional odds were ever used in Vegas, outside of horse racing or futures bets. But if they were, they changed in the interest of simplicity.

And yes, there’s a simple way to easily understand a money line. Simply move the decimal point 2 digits to the left.

In the example used above, -150+130 would be 1.5-1 and 1-1.3, or $150 to win $100 on the favorite and $100 to win $130 on the dog.

This simple conversion helps especially on longshots, which can be confusing. An entry listed as +10000 is easily understood if, again, you move the decimal two to the left. Doing so, you'll come up with the actual price of 100-1.

No part of this answer may be reproduced or utilized in any form or by any means, electronic or mechanical, without the written permission of the publisher.

Have a question that hasn't been answered? Email us with your suggestion.

Missed a Question of the Day?

Have a Question?

Tomorrow's Question

Has Clark County ever considered legalizing prostitution?

Comments

Jackie Jan-29-2022

I like the ancient method

Back in my day you bet a score spread.
One team with added score points verses the favorite.
Simple to understand and your bet didn't have to be for $100
That ended when bookies got greedy as hell.
A year or so ago I tried to bet on a sport team an when I was told I had to bet $150 to win $100, no lesser amount allowed,well, I simply walked away.

Kevin Rough Jan-29-2022

+/-

When the number is + that is how much you win when betting $100.  So if the number is +150 and you bet $100, you win $150 plus get your $100 back for $250 total.

If the number is - that is much you have to bet to win $100.  So if the number is -150 you have to bet $150 to win $100 and get your $150 back.

And at most books these can be divided or multiplied as necessary.

VegasVic Jan-29-2022

@Jackie

You can still bet spreads, in fact that's more popular than betting money lines in football.

Pat Higgins Jan-29-2022

Big tex

At best all of this is just too confusing so I simply never go to a sports book unless I simply want to watch a game.  I never bet.   More power to those who understands what is going on.

Dorothy Kahhan Jan-29-2022

Still confused

So in the example given, you bet $150 to win $100.... why would I want to do that unless I get my original $150 back in addition to the $100 win. And in the other case, I bet $100 to win $130, so in addition to the $130 win, do I get my original $100 bet back as well...   and the only way to lose your $100 is if your bet doesn't win. It would have helped to go through these examples that I've laid out, as I'm sure I'm not the only one confused.

[email protected] Jan-29-2022

Great Summary

Kevin Rough's explanation is the best I've heard.

Ray Jan-29-2022

Smaller amounts

I have never been to a bookie that would not accept smaller increments. The examples showed would be $15 to win $10 and $10 to win $13. And most sports (other than football and basketball) don't have enough scoring to make point spreads reasonable. I also understand Dorothy's confusion. In all sports betting (unlike slot machines) your win includes getting the amount you bet back in addition to the win. Most tickets will print out the actual value of the ticket if it wins.

[email protected] Jan-29-2022

Money Lines

I have to admit that these make more sense than what they used to use for sports like baseball and hockey.  When I first started going to casinos a baseball game would have something like 7 listed after one team and 6.5 after the other.  I had now idea what these meant, and don't to this day.  So -120 +110 do make more sense.

I have to admit that as a mathematician odds like 3:2 or 2:5 feel more natural to me than -150 and +160, but I do see that they make sense as long as the player can keep the +'s and -'s straight!

VegasVic Jan-29-2022

@ Dorothy

Yes you get your original bet.  If you bet $130 to win $100 you would collect $230.  You are risking more than you can win because you are betting on the favorite at -130.  If you bet on an underdog you would be $100 to win $230 at +130.  So  you are risking less because you are betting the dog.

Question of the Day - 29 January 2022

Comments