How soccer luck is measured, and how well it holds up

The data

2025-26 and 2026-27 are built from openfootball: fixtures, results and, for finished matches, who scored and when. It is in the public domain (CC0) and has no shots, so there is no expected goals and no finishing luck. Volunteers keep its files up to date, so the newest matchdays can take days or weeks to arrive; each page says how far the results run. For the Bundesliga a match openfootball has no result for yet comes from OpenLigaDB (Open Database License), a community database that is usually a few hours behind; where both have a match they agree on its score (all 306 matches of 2025-26), and openfootball’s fixtures, dates and kickoff times stay. The forecasts and their tests use ten seasons of it (2016-17 to 2025-26, the Premier League, La Liga and the Bundesliga: 10,660 matches).

Goals alone

The replay. Without shots a match can only be replayed from what its two sides’ goals say. Each club is rated, by ridge regression, on the goal difference of every match of the season (a match counts at most 3 goals) and on the goals in its matches; the home edge and the scoring level are read off the season itself. The two ratings give each side a Poisson number of goals, with draws made a little likelier than two independent counts say, and the match is replayed 4,000 times from that. A knockout tie level after 90 minutes plays 30 more at a third of the scoring rate, then penalties, a coin flip. Because the ratings are built from the same season’s goals, the match itself is part of what rated its teams: the replay is what the goals say, which is a different thing from what we expected beforehand (that is the prediction).

What luck means here. A side’s luck is the gap between the points it has and the points its goals earn (its goal points): it shows up as winning one-goal games, losing heavy defeats, a late winner. Own goals and penalty shootouts are luck as everywhere. It cannot show whether a side made its goals, only whether its goals turned into points. A match’s luck index, lucky or expected, is how far the result was from what the goals say: a win the goals gave 30% scores +70.

Does it work? Not as well as with shots, and we say so. Each measure over a club’s first matchdays against its points a match over the rest of that season (r², 580 club-seasons: ten seasons of the Premier League, La Liga and the Bundesliga):

The points a side’s goals earn predict the rest of a season about as well as the points it has, and a little worse than plain goal difference. So from goals alone, adjusting the table shows how the points were won; it is not a better forecast than the real table, and in the first ten matchdays the gaps are mostly noise. Shots are what make luck-adjusting pay.

Forecasts

The predictions for the matches ahead rate every club on two results of the matches it has played, all of the 90 minutes: the goal difference (a match counts at most 3 goals) and the goals in its matches (how open they are), by ridge regression of strength 4 matches. A club starts the season from last season’s rating, with 90% of its distance from average kept (a club new to the league starts like last season’s weakest), and the matches played pull it away from there. Home advantage is worth about a third of a goal. The expected margin and total give each side a Poisson number of goals, with draws made a little more likely than two independent counts say, and the grid of scores gives win, draw and loss.

Ten seasons of the Premier League, La Liga and the Bundesliga (10,660 matches), each forecast from the matches played before its matchday. The strength and the share of last season kept were picked on 2016-17 to 2020-21; the model was then scored, never refitted, on the 5,330 matches of 2021-22 to 2025-26: ranked probability score 0.200, against 0.201 for ratings from the table’s points alone and 0.229 for the league’s usual shares of home wins, draws and away wins. The favourite won 70.4% of the matches that had a winner. The full test.

Win probability

The line on each match page is the chance of winning from the score and the minutes left, with goals for the rest of the match at the league’s rates (1.51 home and 1.13 away a match; the average at a tournament’s neutral grounds), a draw counted half. For the seasons built from goals alone the rates are that season’s own, and a match whose scorers and minutes our source does not list has no line.

Known limits

• No betting line, so no “before kickoff” or “same teams, fresh game” number from a line.
• The forecasts leave out line-ups, injuries, suspensions and transfers.
• From goals alone we cannot see chances: a side that won 1–0 on one shot looks the same as one that won it by dominating. The shot-based seasons can tell them apart.
• Our goals source is kept by volunteers. When it lags, the pages show the matches it has, and say how far they run; the matches in between appear when it catches up.