Thirty-one county teams from the island of Ireland compete; Kilkenny do not participate.
London did not participate, due to restrictions around travel in place to deal with the COVID-19 pandemic.
[1][2] In December 2020, it was announced that each division would be divided into North and South sections in order to reduce fixtures and minimise cross-border matches.
[5][6][7] In February 2021, it was announced that the league would be delayed due to the impact of the COVID-19 pandemic on Gaelic games and that cancelling it would be a last resort.
[17] As per the Official GAA Guide - Part 1 - Section 6.21[18] - If two teams in the same group are equal on points on completion of the group phase, the following tie-breaking criteria are applied: If three or more teams in the same group are equal on points on completion of the group phase, the following tie-breaking criteria are applied: In the event that two teams or more finish with equal points, but have been affected by a disqualification, loss of game on a proven objection, retirement or walkover, the tie shall be decided by the following means: