Custom devig & sharp books

Two knobs, one fair price

The fair, no-vig price behind every +EV bet comes from two choices you control: the devig mode (the math used to remove a sharp book's margin) and the sharp books (which books feed the calculation, and how much each counts). For the concepts themselves, see Devigging & fair value and Sharp books. This page is about the knobs.

Choosing a devig mode

The Devig Mode filter offers five methods for converting a sharp book's two-sided odds into a single no-vig probability:

• Power — the default, and a reasonable middle ground for most markets.
• Multiplicative — splits the vig proportionally across outcomes.
• Additive — removes an equal share of the margin from each side.
• Probit — works on the normal-distribution scale, which can fit point-spread style markets.
• Worst — the most conservative; it takes the least favourable devigged price, shrinking borderline edges so fewer bets qualify.

Different methods produce slightly different fair prices, especially on lopsided lines. If a method consistently surfaces edges that vanish when you check the book, try a more conservative one.

The sharp-book menu

Open Sharp Books to see a ring summarizing your selected books and their relative weights. Choose Edit sharps to open the full editor. The ring describes your configuration; each market may use only the books that qualify for that comparison.

• Find and add books: use search to find a book, then its add button to include it. Selected books appear first, followed by Other books.
• Remove a book: use its remove button to exclude it from your reference model.
• Weight: each selected book has a slider from 0 to 100. A weight of 100 gives twice the weighting of 50 when both books qualify; these are relative weights, not percentages of a required total.
• Required: turn on a book's Required toggle when its qualifying price must be present. Leave it off to keep that book optional.
• League preferences: use the settings button beside a book to adjust its sport and league scope and Min Market Liquidity.
• Min sharps: use the slider or number field to set the minimum number of qualifying contributors. Raising it can reduce the number of bets shown.

Clear all removes your selected books. Done closes the editor. On a phone the editor fills the screen; you can also tap the back arrow at the top left or swipe right to close it. Save your configuration in a filter preset to return to it later.

A sensible starting point

The Recommended default weights the sharpest books most heavily, keeps everything optional, and sets a low Min Sharps. Positive EV also starts with Max Vig at 10%, which leaves a sharp book out of the fair price when its own prices carry a larger margin. You can adjust or clear that limit in Filters & settings.

Raise Min Sharps for more agreement, lower a noisy book's weight, or switch to the Worst devig mode as you learn which settings suit the markets you follow.

Using the editor in Fantasy

Fantasy uses the same editor under Model > Custom > Edit sharps, but saves its own configuration. Adjustments in one tool do not carry over to the other.

Fantasy Custom can also price supported line discrepancies and applies its own per-book margin and liquidity checks. Its Max vig per book works like Positive EV's Max Vig %, checking each book before blending, but the two are set separately. See Fantasy model settings.