How Do Money Lines Work in Sports Gambling?
Last blog, we spoke about odds and how sports books make them in their favor so when they take on a volume of bets, they are statistically (almost) guaranteed to make money. The next thing that piqued my interest was something I frequently find myself betting on: money lines!
Now what is a money line? A money line is one of the easiest bets to make in sports as you are just gambling on which team you think is going to win straight up. The official money line is presented in terms of how much you need to wager to win a $100 (if the team is the favorite) OR how much you would win if you wagered $100 (if the team is the underdog).
FOR EXAMPLE:
Tonight, my Philadelphia 76ers are playing against the Toronto Raptors. As of 8:04 PM, 5Dimes (a sports book) has the 76ers money line at +103 (meaning you WIN $103 for placing a $100 bet) and the Raptors at -113 (meaning you have to BET $113 to win $100). This is a VERY tight line, but that is only because it is the playoffs and these teams are very competitive.
HOW ARE THE BOOKS PROFITING FROM THIS LINE?
To explain this, we will use the same approach we used last blog and calculate what 5Dimes believe is the percent chance of the 76ers and the Raptors winning based on the money line.
Let’s start with the favorites (Raptors) and explain how that math works. If the team is showing a favorite money line (meaning they have a negative sign in front of the number), the equation to calculate percent chance is as follows (using the Raptors ML for the example):
-113 / (-113 - 100)
-113 / -213 = 53.05%
Now let’s move to the underdogs, my Philadelphia 76ers. To calculate their percent chance of winning, the equation is as follows:
100 / (103+100)
100 / 203 = 49.26%
These odds add up to 102.31%, which as we know represents a 2.31% favor for the book. Let’s now look at Bovada (another book), who seems to think very highly of the Raptors in this game. They have the Raptors at -750 and the 76ers at +475.
For the Raptors: -750 / -850 = 88.24%
For the 76ers: 100 / 575 = 17.39 %
88.24 + 17.39 = 105.63%
Even more favoritism for the bad guys!
As you can see, sports books all across the country are reading these games differently and are creating wildly different lines. This can lead to arbitrage opportunities, which I briefly alluded to in my last blog post.
Arbitrage gambling is a situation where you make bets and are guaranteed profit by taking advantage of multiple books offering different lines on the game. People on Wall Street do this all the time with stocks, but we are just looking at this in the field of sports gambling.
Equipped with our knowledge on money lines, let’s look at a potential arbitrage opportunity with the Denver Nuggets and Portland Trailblazers game tonight (since I looked and there aren’t any readily available opportunities with the 76ers game).
Bovada has a money line of +300 for the Trailblazers tonight while 5Dimes has a money line of +155 for the Nuggets tonight. The math for this is almost too easy!
If I were to bet $100 on the Trailblazers to win with Bovada and $100 on the Nuggets to win with 5Dimes, here is how each potential outcome (only two) would affect me financially:
Hm. Now, I may not have received the highest grades in business school, but this seems like a pretty easy business decision. Find the arbitrage opportunity. Make your bet. Make your money!!!
IF SO EASY, WHY AREN’T MORE PEOPLE DOING IT?
Since sports gambling still isn’t officially legal all over the U.S., people don’t have as much access to a variety of sports books to place these kinds of bets. The sports books mentioned above have a long list of criteria that you must be in compliance with to bet, including location and currency for gambling (some only accept cryptocurrency). However, when sports gambling becomes more legal across the U.S., there should be plenty of sports book market inefficency opportunities for savvy people to capitalize on.
WHAT’S NEXT FOR ME?
Well, in terms of Python and Data Science, I’ve learned many tricks that can be helpful in terms of sifting through data quickly and finding opportunities. Since learning Pandas (yeah, not the animals, the data software library), I’ve learned how to digest a large quantity of data. The key/goal is to create an algorithm/program that successfully cleans, filters, and returns data to me that I want (such as arbitrage opportunities)!
I’ve been messing around with a few things now that I’m 3 weeks through The Flatiron School, but I still have plenty more to learn and keeping an open mind for new ways to approach this topic going forward! Stay tuned!
OH AND BY THE WAY….
The 76ers won and forced a Game 7! Take that book makers!