https://matteocampagna.com/en/registry/competition/groups-widen-faster-than-distance Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/competition/groups-widen-faster-than-distanceTwo papers by the same researcher answer the question by reading competition scores. The first, on two major international competitions in 2013, finds that at seventy metres on the 122 cm face archers score as they do at fifty metres on the 80 cm face, whereas if the group grew in proportion to distance the equivalence would fall at seventy-six metres; and the gap between the two distances grows with the archer's level, which is the opposite of what you would expect if the angular error always stayed the same. The second finds the same equivalence at five world-level competitions with little wind between 2007 and 2009 and turns it into a model: at seventy metres about three quarters of the points lost come from errors that grow in step with distance and a quarter from errors that grow with its square, among them the wind, whose drift grows in exactly that way according to ballistic models. Two limits remain. Everything goes through scores, which mix up how wide the group is with where its centre sits, and the one study that measured group width at several distances, on eight archers, describes the relationship as not significant. And the share that grows with the square is fixed by a calibration the author chose, not derived from the coordinates of the impacts.claim:gruppo-proporzionale-distanza:revision:2026-09-08:2Tue, 08 Sep 2026 08:00:00 GMT https://matteocampagna.com/en/registry/competition/groups-widen-faster-than-distance#storiaBetween 2019 and 2020 three new papers by the same researcher stay at the level of models. A dynamic model of flight in wind repeats that drift grows with the square of distance; the Archery Australia scoring model gives an archer scoring about 700 a group of 38.3 millimetres at seventy metres and 25.6 at fifty, a ratio of 1.5 against 1.4 for the distances, but that is an assumption built into the model; and the score curves for recurve at seventy metres and compound at fifty coincide because the model is calibrated that way. No new measurement on archers: the status stays reported.claim:gruppo-proporzionale-distanza:status_change:2026-07-27:riportatoMon, 27 Jul 2026 08:00:00 GMT https://matteocampagna.com/en/registry/competition/groups-widen-faster-than-distanceclaim:gruppo-proporzionale-distanza:new_claim:2026-05-07:non_studiatoThu, 07 May 2026 08:00:00 GMT