Asian handicap football probability calculator from xG

Version football-asian-handicap-conformance/1.0.0 fixes ten synthetic inputs across integer, half and quarter handicaps, both selected sides and zero, positive and negative feasible rho. Every row publishes all five probabilities, the split components, push-aware fair odds and the zero-expected-net check.

These are formula conformance vectors—not fixtures, observed matches, fitted performance, bookmaker prices or recommendations. The release is licensed under CC BY 4.0.

Start with a probability for every final score. For each score, apply the selected team's handicap to its goal margin, classify the settlement, and add that score's probability to one of five mutually exclusive states. The five unrounded probabilities are then normalized to sum to one.

This tool builds the score distribution from the two xG means using independent Poisson by default. A user-selected non-zero rho applies the Dixon–Coles adjustment to 0–0, 0–1, 1–0 and 1–1 only. Neither option proves that the input xG is accurate.

A quarter handicap is two equal mathematical components. The calculator settles both components against every score before combining them into a full or half outcome.

A reciprocal price is correct only for a simple all-or-nothing event. At decimal odds O, a full win contributes O − 1 units of net return, a half win contributes ½(O − 1), a push contributes zero, a half loss contributes −½ and a full loss contributes −1.

Solving that expected net for zero produces the displayed fair price. The calculator checks the unrounded result numerically; this is a formula audit, not evidence that an offered market price is good or that any input model beats the market.

Independent Poisson assumes the two team goal counts are independent once their means are fixed. Dixon–Coles changes only four low-score cells through rho. The feasible rho interval shown by the calculator is strict because every adjusted cell must remain positive.

Use the xG Poisson score calculator to inspect the full score matrix, the Dixon–Coles calculator to isolate the rho correction, and the held-out Poisson versus Dixon–Coles benchmark to see a real walk-forward comparison. This page owns only the net-goal handicap settlement question.

The split-line examples are grounded in published football betting rules, but an operator's current terms decide which period counts, whether extra time is excluded, and how an abandoned, postponed or void match is handled. This tool does not claim a universal operational ruling.

1. Gambling Regulatory Authority of Singapore, Football Betting Game Rules — regulator-published Asian Handicap and quarter-line settlement examples.
2. Singapore Pools, Asian Handicap bet-type explainer — public line and outcome illustrations.
3. Maher (1982), Modelling association football scores — independent score-model foundation.
4. Dixon and Coles (1997), Modelling association football scores and inefficiencies in the football betting market — low-score correction foundation.

These sources define rules or modelling ideas. They do not endorse this implementation, validate a future Football Proof AIprediction model or establish profitability.