Reading negative American odds
A negative number marks the favored side of the price. At -150, a $150 stake would return $100 in profit plus the original stake if the selection wins. You can use any stake size; $150 and $100 are simply the convention used to describe the ratio.
The break-even probability at -150 is 150 divided by 250, or 60%. If your true probability estimate is below 60%, the price does not offer positive expected value under that estimate.
Reading positive American odds
A positive number describes the profit on a $100 stake. At +150, a $100 stake would return $150 in profit plus the original stake if the selection wins.
The break-even probability at +150 is 100 divided by 250, or 40%. A larger positive number means a larger potential payout and a lower implied probability.
A quick comparison table
Common prices become easier to recognize with repetition: -200 implies 66.7%, -150 implies 60%, -110 implies 52.4%, +100 implies 50%, +150 implies 40%, and +200 implies 33.3%.
Those are raw implied probabilities. They answer the break-even question at the listed price, but they have not removed the sportsbook’s margin.
Price matters even when the pick stays the same
Suppose the same selection is +120 at one book and +105 at another. The +120 price implies 45.5%; +105 implies 48.8%. The outcome is identical, but the required win rate and potential return are not.
This is why a bet can be directionally reasonable and still be poorly priced. The pick answers ‘what might happen.’ The odds answer ‘what are you being paid if it does.’ Both belong in the decision.
Probability is not certainty
An implied probability of 60% still leaves a 40% loss probability before accounting for model error. A single result cannot prove whether a price was good. Evaluate the reasoning and price separately from the outcome.