How we calculate fair value

Odds come from a commercial odds feed covering 17 sportsbooks & exchanges — DraftKings, FanDuel, BetMGM, Caesars, BetRivers, theScore, Fanatics, Hard Rock, and Circa — plus Pinnacle as a sharp reference line, across 16 sports. Inside the app you control the refresh interval per scanner, from every 30 seconds down to every 1 second.

Every response is stamped with the time it was fetched, and each scanner shows an "Updated Ns ago" indicator — so you always know exactly how fresh the prices you're looking at are.

Sportsbook prices embed a margin ("vig"): implied probabilities across a market add up to more than 100%. To judge whether a price is good, we first back out a fair, no-vig probability. You choose the method:

• Pinnacle baseline — use Pinnacle's no-vig line as fair. Pinnacle runs the sharpest widely-quoted market, so when it prices a game this is the most accurate public read available. Markets Pinnacle doesn't price fall back to multiplicative.
• Multiplicative — divide each side's implied probability by the market total so they sum to exactly 100%. The industry-standard default.
• Shin — corrects for longshot bias (books shade underdog prices more than favorites). Better on markets with heavy favorites.
• Power — exponential normalization; a good general-purpose alternative when multiplicative over- or under-corrects.

Try it yourself with the free No-Vig Calculator.

Once we have a fair win probability, EV is arithmetic:

EV% = (decimal odds × fair win probability − 1) × 100

A +3% EV bet returns, on average, $1.03 for every $1.00 staked — before variance. EV says nothing about any single bet's outcome; it's a long-run average, and short-term results will swing well above and below it.

The bet tracker grades every logged bet against two benchmarks: the book's own closing price, and Pinnacle's closing no-vig line — snapshotted in the final minutes before game start. Consistently beating the close, especially Pinnacle's, is the most widely accepted evidence that a bettor has real edge rather than a lucky streak.

• We don't guarantee profits, and we don't publish earnings claims.
• We don't accept wagers or operate as a sportsbook — StackDubs is an informational analytics tool.
• We don't show numbers we can't back: every figure on this site comes from live product data or the formulas above.
• Arbitrage "guarantees" hold only when both legs fill at the quoted prices — lines move, and we say so in the app.