Statistical newsworthiness in football: a validity filter for league-table archives and a points-record detector with base-rate control

We describe the method by which calcio.it decides when a statistical fact about a football team is a publishable news item. The method has three parts: (1) a validity filter for historical league-table archives, which excludes seasons whose table cannot be read as a single table; (2) a detector of records in points after N matches, with a depth threshold of k ≥ 5 seasons of the same team; (3) a base-rate control, under which a detector is switched on only if, measured retrospectively over the whole archive, the fact it flags is confirmed at the end of the season at least 3 times as often as for teams that do not trigger it. On our archive (68 competitions, 3,978 team-seasons eligible at matchday 5) the detector yields a ratio of 3.71. The resulting news items are written by an artificial-intelligence system using only the numbers in a fact sheet, and are published after human review.