~/guides · the math, worked
6 guidesNo picks, no tips — just the arithmetic behind a price, shown step by step. Each guide gives the exact formula, worked examples you can replicate, and a plain-language reading of what the number means. Reference material, not advice.
// Edge & staking
Kelly staking in practice
The Kelly formula answers one question — how much — and it is unforgiving about a wrong edge estimate. This guide is the operational companion to the definition: fractional sizing, exposure caps, correlated books and the recalculation cadence pros actually run.
Value betting & expected value
A value bet is not a bet you expect to win — it is a bet priced above its fair probability. This guide builds expected value from first principles, shows how to compare your estimate to a no-vig fair line, and explains why most 'sure things' are negative EV.
// Odds mechanics
Converting odds: decimal, fractional & American
The three odds formats are the same number wearing three costumes. This guide gives the exact conversion formulas in every direction, worked line by line, plus the rounding traps that make a converted price disagree with the book by a cent.
Implied probability & overround
Every price is a probability with a tax bolted on. Here is how to turn any odds format into an implied probability, why the two sides of a market sum to more than 100%, and how to measure that excess — the overround — on two-way and multi-way books.
Vig, hold & margin math
Vig, juice, hold, margin, overround — five words for one idea, calculated two different ways. This guide separates the theoretical margin from the realised hold, works the math on two-way and three-way markets, and shows what widening juice does to a break-even win rate.