Probability
Desk
This is not a sportsbook. The desk takes no bets, moves no money, and sells no picks — it does arithmetic the books would rather you didn’t. Strip the vig out of a price, hold your own probability up against what’s left, and size the stake like a grown-up. Most visits end the same way, and that’s the point: the desk’s favourite word is “no.” Manual entry only — you bring the numbers, the desk brings the honesty.
01Devig the market
A two-way price sums to more than 100% because the book charges rent. Enter both sides; the desk strips the margin proportionally and hands you the fair probabilities — the numbers the market actually believes, before its cut.
Method: proportional devig — each side’s implied probability divided by their sum. Other methods (additive, Shin) exist and disagree most on lopsided moneylines; proportional is the honest default, not the final word.
02The verdict machine
Your model says a side wins more often than the price admits? Prove it. The desk compares your probability against the break-even probability implied by the price you can actually get — and it only says yes when the math does. Everything else is a no, delivered without ceremony.
Read this before the green box seduces you: Kelly assumes your probability is exact. It never is. That’s why the default is quarter-Kelly with a hard cap, and why hundreds of graded bets — not one hot weekend — are what separate an edge from a mood.
03Line shop
Same bet, different books, different prices — and the difference is worth more, more reliably, than most model tweaks. Enter the price for the same side at every book you have; the desk crowns the best one and invoices the worst for what it would have cost you.
| Book | Odds (American) | Implied prob | Profit on $100 |
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