dogfight; three-way playoff
A playoff format where three participants compete in a round-robin style, with the winner of each bout staying on to face the next opponent. Originally from sumo, but now used more broadly for any three-way tiebreaker.
A three-way playoff was held in the grand sumo tournament's championship match.
Since the three had the same record, it was decided to determine the winner by a three-way playoff.
sumo three-way playoff
Specifically the sumo playoff format where three wrestlers compete in a round-robin; the winner of each bout stays on to face the next wrestler.
In a sumo three-way playoff, the wrestler who wins first fights the next opponent.
From 巴 (tomoe), a comma-shaped design often used in a threefold pattern, suggesting a three-way contest, plus 戦 (sen, 'battle').