Money Line Betting

by Betrics Co. Author Sal Cacciatore

How the money line works

A money line bet is a wager on who will win the game, with lines represented in positive and negative numbers. But what do these numbers mean?

If a team is listed with a negative number, it is the favorite, and if it has a positive number, it is the underdog.

The negative number represents the amount of money a bettor would need to wager on the favorite to win $100. For example, if New York is a -300 favorite, this means a $300 bet would win $100 (while a $150 bet would win $50, and a $600 bet would win $200).

In the case of the positive number, this shows how much money a $100 bet on the underdog would win. For example, if Florida is a +400 underdog, a $100 bet on Florida would win $400 (a $200 bet would win $800, etc.).

Implied Win Probability

Another important aspect of money line betting is market-implied win probability. In addition to telling you how much money your bet would yield, money lines can also represent the chances the bookmaker thinks a team will win.

If a team is a -300 favorite by the money line, this implies a 75% chance this team will win. How did we arrive at that number?

Simply take the number after the minus sign and divide it by that number plus 100. The formula looks like this:

Money line/(Money line + 100).

In our case, 300/400 = 0.75.

The win probability formula for underdogs differs from that for favorites. For underdogs, we divide 100 by the money line plus 100.

The formula is 100/(money line +100).

For example, if a team is a +400 underdog, those odds imply they have a 20% chance of winning. The math is: 100/(400+100) = 0.20.

Knowing these formulas is crucial to money line bettors because it informs whether or not a play has a positive expected value. If, on the one hand, a bettor believes a favorite has an 80% chance of winning, but it is only a -200 favorite (66.7% implied win probability), this could be a bet worth making.

On the other hand, if he or she believes the favorite has just a 60% chance of winning, the bettor should probably avoid it at -200.