Turn any odds into the chance of winning they imply, with the break-even bar.

Every price carries a chance inside it. A price of -200 implies about 66.7%. A price of +150 implies about 40%. That number is the break-even chance: how often the bet must win just to leave you even.

It is easy to mix up with the real chance the bet wins. They are two different numbers. The implied chance is what the price needs. The true chance is what actually happens over many bets. A bet is only worth making when the true chance beats the one baked into the price.

Both sides of a game add up to more than 100%. That extra is the book's cut, which is why a single price always implies a slightly higher chance than fair.