A Crazy Ninja Odds alternative that puts the spread between devig methods in one number
Free devigger with four methods and a worst case, free to use — read 2026-09-24, source.
Try it on your own price
Type the two sides of any market. You get the consensus fair probability and how far the four methods disagree about it — the number a one-figure no-vig calculator leaves out.
Loading the engine’s answers…
Every answer here was computed by the same engine that built this page, for all 6,737 two-way markets between −600 and +600. Nothing is calculated in your browser: a second implementation drifts from the first, and the drift is invisible until someone bets on it. Prices that do not form a real two-way market are refused rather than rounded into one.
What Crazy Ninja Odds does, and what Bookbreaker adds
Crazy Ninja Odds is free, and its devigger can show all four methods and a worst case (read 2026-09-24, source). Bookbreaker adds the spread between methods as one number, the chance the price is still there when your bet lands, and arb stakes in round numbers — offline on your Mac.
Side by side
| Crazy Ninja Odds, as published | Bookbreaker, as computed | |
|---|---|---|
| What it advertises | Free devigger with four methods and a worst case — read 2026-09-24, source | 27 venues catalogued across 50 states |
| The gap we recorded | Shows the four methods and a worst case, not the spread between them as one number — read 2026-09-24, source | The spread between the four methods as one number, next to each method's fair price |
Every cell in the middle column carries the date it was read and a link to where. Some gaps are something we looked for and did not find; others are something the tool states plainly about how it works. Neither is a claim about what it could do, only about what it published on that date. The right column is computed by running this engine when the page was built.
How much the method choice is worth
4additive, multiplicative, power and Shin, side by side
0.39%how far four defensible methods disagree about one price
-7.0% to +18.9%around a headline 5.91%
Crazy Ninja Odds' worst case takes the most conservative of the methods (read 2026-09-24, source), which is a careful way to bet. Bookbreaker also tells you how far apart the methods are, as one number, so you can see when the fair price is too uncertain to bet against at all.
Why every tool in this list has the same blind spot → · Bookbreaker is free →
Prices change. This one carries the date it was read.