One-way derived +EV

Normal EV math needs all outcomes of a market at a book so the vig can be removed. If Circa posts Over 9.5 and Under 9.5, EVantage can devig that pair. If a book only posts one side, that book is dropped from the fair line.

Derive One-Way Odds is an experimental setting that estimates the missing side so that book can still be used to estimate fair odds. Turn it on in the +EV Scanner only after you understand what it is inventing.

What it does

On two-way markets, if a book has only one outcome, EVantage:

  1. Looks at the posted price
  2. Estimates a typical vig for a number that size
  3. Assigns the leftover implied probability to the missing side

That invented price is estimated. It will not show up as a bet you can take. It only exists so the book can sit in Devig Books and contribute to the fair line.

Why you would use it

Some books and exchanges regularly post one side only for player props or niche markets. Without this toggle, those quotes never enter the fair line, even if you trust the source.

One-way derivation lets you keep a sharp or exchange number in the mix when the other side was never listed. It also unlocks a few markets the scanner otherwise skips for lack of a clean two-way book.

Why it is experimental

The missing side is a guess. When a sportsbook only posts one side, they often give a terrible price to ensure they don't take on any risk.

How to use it safely

  • Leave it off for everyday scanning.
  • Turn it on when you specifically want one-sided quotes (a sharp Over-only, an exchange Yes) in the fair line.
  • Keep Min Devig Books up so one invented pair cannot run the number.
  • Prefer it alongside real two-way books (Pinnacle, Circa, FanDuel both sides), not instead of them.
  • Treat the resulting EV% as weaker than a normal two-way devig. Confirm with line movement and Trusting +EV signals.

Key takeaways

  • One-way derivation invents the missing side so a one-sided book can be used to devig. It does not create a bet.
  • The invented side is a vig estimate, not a real price. The signal is weaker than a true two-way pair.
  • Keep it off unless you know why you need those one-sided quotes in the fair line.