This is part of: Players in space.
Here we'll put activities where there are two sides in spatial relation to each other. Duos will fit into this category, but also symmetrical teams.
In improvised music, the duo format holds a particular significance. Some players maintain that the duo is so special and forceful that every band, at its core, forms itself around the energy (whether complimentary or agonistic) between two players.
(DiPiero 2022, 93)
An interesting case to look at would be a symmetry between teams that is never spatial, but appears in time. In many sports an attacking team (often with a possession of a ball) moves much differently than defenders. E.g. in basketball players place themselves symmetrically only at the very start of the game (tip off), and in many sports — never. Such a layout is only potentially mirrored, never in practice, but we'll put these type of games here anyway.