Sprint medley relay
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.
Sprint medley usually consists of two shorter sprints, followed by two single longer events. Usual conduct for safety is to run the shorter events first, in lanes to allow faster moving sprinters to exchange without interference. And faster moving athletes will have a more consistent tempo to prepare a handoff than with longer sprinters who are more prone to decelerate inconsistently as they finish their leg. By running two shorter sprints, mathematically the events can be conducted over an even number of laps.