In case the author is here: What's the difference between "win probability of win" and "odds", please? The seem the same thing to me. And also, what are "decimal" vs. "american" odds, please? Thanks.
American odds (also sometimes called “moneyline” odds) have two presentations.
- If the odds quoted are positive it indicates the net payout (excluding stake) from a bet of $100 dollars. So I place a bet of 1 dollar at moneyline odds of 150 it pays me 1.5 plus my original stake back. 150/100 * 1 + 1 = 2.5. So payout = stake + (odds/100 * stake) . A positive moneyline odds number means an underdog.
- If the odds quoted are negative it’s how much you need to bet to win $100 (excluding stake). So if I place $1 at moneyline odds of -150 and it pays out I get 1 * 100/150 + 1 =1.667. Therefore payout = stake + (100/abs(odds) * stake). A negative moneyline odds number indicates a favourite. The higher the absolute value, the bigger the favourite as far as the house is concerned.