The sprint medley relay (SMR) is a track and field event in which teams of four athletes compete over sprinting distances as part of a relay race. Unlike most track relays, each member of the team runs a different distance. The sprint medley is rather uncommon, run most frequently at non-championship track meets which are focused on relays. Since these are not championship events, specific criteria for the event are not in common rulebooks. This leads to localized variations.