How we calculate the things that matter

• True Value

  How we score welcome bonuses on a 3% blended-margin basis with a published reference scenario. Includes the 33× wagering-requirement impossibility threshold, per-anchor formulas, and worked examples.

• House edge

  How we compute the per-game expected loss ranges in /tools/house-edge. Citations to Wizard of Odds + UKGC RTP datasets. Why we show ranges, not single numbers.

• Odds conversion

  The formulas behind /tools/odds-converter. Conversions across American, Decimal, Fractional, and Implied Probability — and what bookmaker vig does to the implied probabilities you read.

• Prediction-market fees

  The published trading-fee formulas behind /tools/fee-calculator for Kalshi, Polymarket, DraftKings, Robinhood and Gemini — primary sources, verification dates, maker/taker handling, and what isn't included (funding costs, bid–ask spread unless entered, slippage, rebates, taxes).

• Platform reviews

  How we research, score, and write platform reviews. The ranking criteria, conflict-of-interest disclosure, and the line between editorial and affiliate.

• Trust & ratings

  Where the number on every platform card comes from — license weighting, complaint resolution, transparency, payout track record.

  Soon

• Affiliate disclosure

  Which platforms compensate us, what that compensation does and doesn't influence, and the wall between editorial and revenue.

New methodology pages get added here as the systems behind them mature. If you spot an error in the math or want a particular assumption better documented, open an issue.