How Do MLB Odds Work?

Most of us have seen sports odds before and understand why a Major League team is favored and the other is a dog — particularly if the Orioles are playing!

MLB betting has many popular options, particularly the runline/spread, moneyline and over/under options. There are prop bets too, which allow you to wager on almost anything which can occur within a baseball match. 

Vegas usually sets the standard and determines the baseball odds for sportsbooks across the United States. Wanting to know the why behind the odds you see in our MLB Bet Hub and sportsbooks America-wide?

All of the answers are here for you, right now!

How are MLB odds determined?

The function of MLB odds making isn’t to truly represent the probability of an outcome occurring. Vegas and sportsbooks actually put forth certain odds to make a profit and in the hopes of attracting bettors to both sides (either team etc). 

Ultimately oddsmakers are in bed with the sportsbooks. They are trying to reduce the risk of sportsbooks losing large. 

That’s why books hate when a big favorite wins, because they lose big. Major League Baseball betting odds certainly aren’t determined on the gut feel of a sports predicting genius. 

Sports statisticians and mathematicians are heavily involved in the odds you see on a sportsbook’s site and app. The X’s and O’s of baseball odds involve an examination of the wider betting market, statistics and data. 

In the case of MLB moneyline and spread bets, odds makers will look at previous matchups, form, injuries and even teams’ strengths and weaknesses to determine the odds. It isn’t that simple of course, algorithms and other nerdy stuff go into it, but this gives you an idea. 

In other words, it’s not too different to Dimers’ predictive analytics model where 10,000 simulations of every MLB game are conducted, based on the variables above, all to give you an unrivaled edge before you make that winning play. 

MORE: Best MLB Betting Strategies

Why are MLB odds not real probabilities?

Like any business, sportsbooks want to make a profit. They don’t sell clothes or shoes, but they do sell odds to you, the bettor. How do they profit? Let’s look at the below.


  • New York Yankees @ Boston Red Sex — Fenway Park
  • Red Sox  -250 (implied probability of 71.43%)
  • Yankees  +200 (implied probability = 33.33%)


For the nerdsters out there, yes those percentages don’t add up. Well, they do, just not to 100% —and, yes, we had to use a calculator. The sum of the two percentages equals 104.76%. How can a baseball game have an implied probability of close to 105%?

It can’t really. The extra 5% is the profit margin this sportsbook is taking home. With such a strategy commonly implemented across America, this is how books will make a profit over time.

Favorites lose = Sportsbooks win

When there’s a big upset during the MLB season, bookmakers rejoice. This is because most of the money is heavily poured on the favorite, meaning the sportsbook takes all of it home. Big favorites losing is a sportsbooks’ golden goose.

Now that you know where odds come from, find the best baseball odds in America with Dimers. We have exclusive promo codes for each of the biggest and most secure sportsbooks. If you’re wanting to succeed at baseball betting, check out our MLB Bet Hub.

MORE: Live Betting on the MLB Explained

Why do sportsbooks have similar odds?

Sports betting is going gangbusters on a global scale. Surprisingly, baseball betting is far more advanced in places like the UK, Australia and across most of Europe and Asia, while it is just getting started in America (Vegas excluded).

Due to the globalization of MLB betting it isn’t uncommon for sportsbooks to simply copy the odds of other books. This method is cost effective and they end up with the same odds without all the data and betting analytics research. 

We don’t know which books copy others but we do know how you can find the best odds for every major sport in the United States.

MORE: How to Bet on MLB Games

How to take advantage of MLB odds

Sportsbooks look to make money off your bets, and set odds in such a way to favor their interests. So, how do we fight back and win money from sports betting?

The answer is simple — take advantage of the edge.

What is the edge, you ask? 

This is where the probability of an event occurring is more likely than the sportsbook’s odds. In other words, our predictive analytics model suggests a baseball team/player has a much better chance of winning than the sportsbooks think.

Taking these bets gives you a better chance of being a successful gambler long-term. Of course, the higher the edge, the better. While you’re not guaranteed a win by betting the edge (they occur on underdogs as frequently as on favorites), taking picks with an edge gives you a greater chance of being profitable well into the future. This is super important when trying to be a successful Major League bettor.

For every major sports match including MLB, NHL, NBA and more, Dimers has the edge and exclusive promotional codes waiting for you.

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