noun
rule prohibiting matches between wrestlers from the same stable
A sumo-specific rule that prevents wrestlers belonging to the same heya (stable) or ichimon (clan) from being matched against each other in tournament bouts, except in playoffs.
系統別総当りのため、同じ部屋の力士同士の対戦は原則として組まれない。
Due to the rule prohibiting matches between wrestlers from the same stable, bouts between wrestlers of the same heya are generally not scheduled.
Compound of 系統 (lineage, system), 別 (by, according to), and 総当り (round-robin). The term literally means 'round-robin by lineage', referring to the sumo scheduling rule that avoids matches within the same stable or clan.