← The +EV course
Glossary
Every term the app uses, in one place. Each one links to the lesson that explains why it matters.
30 terms
- American odds
- The +150 / -110 format. A positive number is what you win on a $100 stake; a negative number is what you must stake to win $100.
- Arbitrage
- Backing every outcome at different books, at prices that leave a small profit whoever wins. Real, rare, and the fastest way to get your account limited.
- Bankroll
- The money set aside for betting and nothing else. Every stake is a percentage of it, which is what stops one bad night from ending the experiment.
- Closing line
- The last price a book offers before the event starts. It is the market's final answer, after every injury, lineup and piece of money has been priced in.
- Closing line value (CLV)
- The gap between the price you got and the closing line. Beating the close consistently is the earliest evidence you are picking good prices rather than getting lucky.
- Commission
- A cut of your PROFIT that an exchange keeps instead of building a fee into the price. You only pay it when you win, and it comes out of the winnings rather than the stake — so a quoted price at a commission book is slightly worse than the same number at a book without one.
- Correlation
- When two bets win or lose together. Two bets on the same game outcome are not two chances — they are one bet at twice the size, and sizing them separately understates the risk.
- De-vigging
- Removing a book's margin from both sides of a market to recover what it really thinks the chances are. The result is the fair price.
- Edge
- How much better the offered price is than the fair one, as a percentage. It is the whole reason a bet is on the feed.
- Expected value (EV)
- Your average profit per dollar if you could make the same bet over and over. Positive means the price is in your favour, whatever happens to this particular bet.
- Fair odds
- The price that matches how likely something actually is — the market's own estimate with the book's cut taken back out.
- Fractional Kelly
- Betting a fixed share of the Kelly stake — a quarter, here. It gives up a little growth for a large reduction in how far the bankroll swings, and it forgives an edge you overestimated.
- Free bet
- A promotional stake that pays out the winnings but not the stake. Worth roughly 70c on the dollar, which is why it is worth using and not worth chasing.
- Grade
- The A+ / A / B label on a card. It is a band of edge, not a confidence rating: A+ is 4% or better, A is 3–4%, B is 2–3%.
- Hold
- The share of all money wagered on a market that the book keeps whichever way it lands. The same idea as vig, stated as the book's take rather than as your cost.
- Implied probability
- The chance a price is quoting, as a percentage. -110 implies 52.4%. Both sides of a real market add up to more than 100%, and the excess is the book's margin.
- Kelly criterion
- A formula for the stake that grows a bankroll fastest given your edge and the price. Full Kelly is correct and unbearably swingy, which is why nobody sensible bets it.
- Ladder
- The row of alternate lines a book offers around the main one — the same bet at a different number and a different price. Sometimes the alternate is the better price.
- Limiting
- A book cutting how much it will take from you, or closing the account. It is what happens to bettors who win, so it is evidence rather than a punishment.
- Line shopping
- Checking every book you have before placing, and betting the best number. It is the single habit that turns a break-even bettor into a winning one.
- One-way market
- A market where only one side is quoted, so there is no opposite price to de-vig against. Fair value has to come from elsewhere, and the edge is less trustworthy for it.
- Parlay
- Several bets combined so all of them must win. A parlay of +EV legs is still +EV — it just swings much harder than the same legs bet separately.
- Player prop
- A bet on one player's numbers rather than the result — points, yards, strikeouts. Priced faster and watched less closely than the main lines, which is where the edge comes from.
- Promo
- A profit boost, no-sweat bet, free bet or odds boost. They are coupons with money on them and they are the easiest profit available to a new account.
- Tout
- Anyone selling picks. The test is simple and almost nobody passes it: a full year of every bet, at the price they actually got.
- Unit
- One standard bet, expressed as a share of a bankroll rather than a dollar figure, so results can be compared between people betting different amounts.
- Variance
- The swing around the average. A profitable strategy still loses ten in a row sometimes, and mistaking that for a broken strategy is how most people quit while ahead of where they started.
- Vig
- The book's built-in fee, baked into both prices rather than charged separately. It is why the two sides of a market add up to more than 100%.
- Volume
- How many bets you make. A small edge is only worth anything repeated a lot of times — one 3% bet is a coin flip, three hundred of them is a result.
How much to bet→See also Kelly criterion, Unit
Closing line value→See also Closing line, Variance
Betting against yourself→See also Parlay
What +EV actually means→See also Edge, Variance
How much to bet→See also Kelly criterion
Promos, boosts and free bets→See also Promo
What +EV actually means→See also Edge
Why the board never adds up→See also Vig
Reading the price→See also American odds, Vig
How much to bet→See also Fractional Kelly, Bankroll
Ladder plays→See also Line shopping
The same bet at five prices→See also Ladder, Fair odds
Parlays and correlation→See also Correlation, Variance
Player props→See also One-way market
How much to bet→See also Bankroll
Why the board never adds up→See also Hold, De-vigging
Education, not betting advice. 21+. Gambling problem? Call or text 1-800-GAMBLER.