What the course covers
The course follows one chain of reasoning. A price tells you what a winning bet pays. That payout implies a chance. Add up the chances on both sides and you find the sportsbook's margin. Multiply prices together and you get a parlay, with the margin multiplied as well. Finally, you set the implied chance against your own estimate to decide whether the price is worth backing.
The five ideas in writing
First, an American price is one number. A minus price is the amount you risk to win $100, and a plus price is the amount you win when you risk $100. The stake comes back with a win.
Second, every price implies a chance. For a minus price the chance is the number divided by itself plus 100, so -150 implies 60%. For a plus price it is 100 divided by the number plus 100, so +200 implies about 33.3%. This is also the rate at which you break even.
Third, a two-way market that adds up to more than 100% carries a margin. Prices of -110 on both sides imply 52.4% each, a total of 104.8%, and dividing each side by the total shows the book's own 50% view.
Fourth, a parlay multiplies decimal prices, and every leg must win. Two -110 legs pay about +264, where two true 50% chances would justify +300.
Fifth, a price has value only when your honest estimate beats the implied chance. At -110 you need to win more than 52.4% of the time. Whether an estimate is honest is the hard part, and the course cannot settle it for you.
Where the course stops
The course teaches arithmetic and a way of thinking. It does not tell you which bets to place, and it cannot give you a better estimate of any game. Real prices change, real offers carry rules the examples leave out, and the safest amount to bet is an amount you could lose without it mattering. For the practical side of using an app, read how to bet on an app. For the rules around staking and limits, see responsible gambling.
Frequently asked questions
How long does the course take?
Each lesson is a few paragraphs, one small tool and two or three questions, so the whole course is short.
Do I have to answer correctly to continue?
Correct answers unlock the next lesson button, but the skip button moves you on at any time. Skipped lessons are not marked as finished.
Is any money involved?
No. Nothing is staked and no account is needed.
Where is my progress stored?
Only in your browser, so it stays on your device and nothing is sent anywhere. Clearing your browser data resets it.
Why -110 in so many examples?
Because -110 on both sides is a common price for spreads and totals at US sportsbooks, and it makes the margin easy to see.