Portugal’s 1990–91 top flight had the fewest teams with a positive goal difference
The fewest teams finishing a season with a positive goal difference appears to be in Portugal’s 1990–91 top flight, when only four of the 20 clubs ended with a positive GD (20%). A caveat in the data noted that Vitória de Setúbal finished with a goal difference of 0, so only 15 of 20 (75%) had a negative GD.
Other high concentrations of negative goal differences in full English seasons were identified by Chris Roe: the 2005–06 second tier (17 of 24 teams, 70.83% negative GD) and two Premier League seasons, 1998–99 and 2017–18, when 14 of 20 teams (70%) finished with a negative GD. Roe also cited an in-season example from Division Three South in 1952–53 when, for a few rounds, 18 of 24 teams had negative GD (75% negative).
Vasco Wackrill highlighted several Portuguese examples with very few positive GD clubs: in 2022–23 only four of 18 teams (22.2%) finished with a positive GD — Benfica, Porto, Braga and Sporting — and the same four were the only non-negative sides in 2017–18 and 2009–10. For 1990–91 he pointed to the large positive differentials of the top sides — Benfica +71, Porto +55, Sporting +35 and Boavista +7 — producing the extreme disparity.
Dirk Maas found a comparable case in Romania’s 1988–89 Divizia A, where only four teams finished with a positive GD, though the fifth-placed team had a GD of 0 so the percentage of negative-GD clubs was described as slightly lower than the Portuguese examples.
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