Every flag,
with the date on it

Identity

Players are matched to transfer records by name and birth year, because our match database holds no transfer-market identifier. A player whose name transliterates differently in the two sources cannot be matched, and reads as not observable; 10 of the flags do. That cuts both ways and is applied identically to the comparison group.

Sample

43 graded flags is a small number. The gap between the flagged and comparison rates is not established at this sample size; it is published so it can be watched, not so it can be quoted as a hit rate.

Retrospective

Flags from seasons that ended before this page first went up were produced by running the rule over history, not published in advance. They are marked by their season, and the rule was fixed before the outcomes were read, but only flags first published from 2026-08-25 onward are a forward record, and that is the part that will matter in a year.

Coverage

The transfer data covers moves in and out of our own competitions. A flagged player who moved between two clubs neither of which touches our leagues would not appear, though by construction that is rare for a player flagged while playing in one of them.

Outcome choice

"Exported" is the outcome because it is the one our data can see cleanly and the one the market pays for. It is not a judgement on the player's career, and a player who stayed and improved is not a miss in any football sense.

Commission a report How the numbers are made