How the model
actually works.

Who builds and runs Matchday?

Matchday is a passion project, currently built and run by one person rather than a company or a team. It's kept intentionally small, free, and focused on getting the model and the data right. If it ever grew a lot, that would mean rethinking how it's maintained and funded — that's a problem for if and when it happens, not something the product is built around today.

Is Matchday betting advice?

No. Matchday shows model estimates and market context for analysis. It does not take bets, process wagers, or provide financial or gambling advice, and it is not affiliated with any bookmaker.

How does Matchday calculate a win probability?

It blends several factors depending on the sport: season record and points, recent form, scoring margin, home advantage, rest days, an Elo rating, an opponent-adjusted rating similar to strength of schedule, and where available a team class or poll rank. Each factor's pull toward one side is shown transparently in the match breakdown.

What does confidence mean?

Confidence is the model's estimated probability that its picked side wins, shown as a percentage. It is an estimate, not a guarantee — games with limited current-season evidence are intentionally shown with more conservative confidence.

What does edge mean?

Edge is the gap between the model's probability for an outcome and the betting market's implied probability for the same outcome. It highlights where the model and the market disagree most, not a recommendation to act on that disagreement.

What is Elo rating?

Elo is a rating that rises after wins and falls after losses, weighted by the strength of the opponent — the same style of rating used in chess, adapted per sport and updated automatically after every graded result.

What is the opponent-adjusted rating?

It is a rating built only from a team's own results and the strength of who they played, correcting a team's raw scoring margin for whether their schedule has been easy or hard so far.

Why does the model sometimes disagree with the betting market?

The market can price in information the model does not see yet, like late injury news or sharp betting activity. The model can weigh things the market is slower to move on, like recent underlying performance. Disagreement is reported as edge, not treated as the market being wrong.

What does Upset Radar mean, and who is the underdog?

The betting market is the baseline. The underdog is the team with the lower consensus market-implied win probability. It is not automatically the lower-ranked team, the less famous team, or simply the side Matchday originally rated lower.

Upset Radar appears when that team is a genuine market underdog and Matchday gives it a win probability at least 6 percentage points higher than the market does. For example, if the market gives a team 22% and Matchday gives it 31%, the radar sees a +9-point underdog edge.

A radar flag is not automatically the official pick. It says the underdog looks more competitive than the market price suggests. Actually changing the official pick to that underdog requires stricter checks: the adjusted probabilities must be close, the matchup must have a high upset/volatility score, and the market gap usually cannot be too wide. If current market odds are unavailable, Matchday normally will not make a pregame upset pick.

How does Matchday track its own accuracy?

Every pick becomes eligible for a verified public lock inside 12 hours of kickoff and is graded only after an official final result; picks are never rewritten afterward. The pipeline verifies that both the lock and grade persisted before a fetch succeeds. In knockout games, the model pick is graded by the team that advances after extra time or penalties while the displayed score remains unchanged. Betting-market comparisons follow the market's own settlement rules. The Scorecard tab shows the full hit rate, calibration by confidence band, and which factors have actually been predictive recently.

Why didn't a pick change even though the market moved?

Picks become eligible for a verified lock inside 12 hours of scheduled kickoff and stay locked. If odds arrive later, only the market-comparison fields around the prediction can be filled; the selected side and confidence cannot change. That's deliberate: a model that could quietly rewrite its own picks after seeing new information wouldn't have an honest track record.

Where does Matchday's data come from?

Licensed and free-tier sports data providers per sport, plus a market-odds provider and public RSS news feeds. The full list of sources and their terms is on the Legal page.

Do I need an account, and is my data private?

No account is required. Personal settings like favorite team, watchlist, and appearance stay in your own browser's local storage rather than on a server. Full details are on the Legal page's privacy section.

Is Matchday a live-score service?

No. Matchday is a pregame and postgame analysis product. In-progress games remain Result pending until the hourly pipeline receives a provider-confirmed final result suitable for grading. It does not promise live clocks, score alerts, or minute-by-minute updates.

How often does the data update?

Production runs an hourly pregame and postgame fetch. Odds are requested only for upcoming games close to kickoff and cached to conserve quota. Browser reloads read the latest published dataset; they do not force providers to publish a result sooner.