A round robin (RR) is simply a nickname for a type of parlay wagering strategy. You take a group of three or more selections and put them in combinations of individual parlays. You could enter these parlays individually yourself, but a lot of sportsbooks allow you to select a round-robin option and do it automatically.

A round-robin tournament (or all-go-away-tournament) is a competition in which each contestant meets every other participant, usually in turn. A round-robin contrasts with an elimination tournament, in which participants/teams are eliminated after a certain number of losses.