The Primer
How it actually works
Evergreen explainers of the mechanics behind a bet type, a price, or a bankroll rule — every worked figure is arithmetic you can re-derive from the numbers on the page. No picks. No affiliates.
The Math · 2026-07-12 · 10 min
Bankroll, units, and the Kelly criterion — how much to actually stake, in numbers you can check
Selection gets the attention; stake size decides how long you survive. This is the plain-arithmetic version of bankroll management — what a unit is, why flat staking is the sane default, and exactly what the Kelly criterion tells you to bet when you genuinely have an edge.
The Math · 2026-07-05 · 10 min
Implied probability and removing the vig — how to turn a price back into a fair chance
Every betting price is a probability in disguise. Convert it, and you can read what the sportsbook thinks a bet's chance really is — but only after you strip out the margin. Here is the conversion in both directions, and the arithmetic that removes the vig from a two-sided market.
Bet Types · 2026-06-28 · 9 min
Futures betting and the field — why an outright ticket bleeds more hold than any single game
Championship futures are fun to hold and expensive to own. Because a futures market prices an entire field at once, the implied probabilities of every contender add up to well over 100%, and the excess — often far larger than a game line's — is locked in the moment you place the bet.
Bet Types · 2026-06-21 · 8 min
Why player props cost more — the overround, in plain arithmetic
Player props feel like the same bet as a side or total, but the price you pay is quietly worse. The reason is the overround: the sum of both sides' implied probabilities. On a standard side it sits near 105%; on a prop it is often higher, and that gap is the extra hold you never see on the slip.
Bet Types · 2026-06-14 · 10 min
Teaser bets, buying points, and key numbers — the arithmetic behind why teasers target 3 and 7
A teaser lets you move the spread in your favor across several bets in exchange for a shorter price. The math that decides whether that trade is any good comes down to one break-even win rate per leg — and to whether the points you buy cross the numbers football games land on most.
Bet Types · 2026-06-07 · 9 min
How parlay odds multiply — and why the house edge compounds every time you add a leg
A parlay pays more because it wins less often, and the sportsbook's take grows on every leg you attach. Here is the multiplication rule in plain arithmetic, the gap between a fair parlay price and the one you are quoted, and why correlated legs are the exception that changes everything.
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