003.001 Introduction to Time Standards

In this series of posts, we’ll examine the nature of qualifying times, motivational times, and time conversions.  USA-S age group swimming uses two types of time standards: qualifying times and motivational times. Qualifying times determine whether an athlete can compete an event; they are most commonly used to restrict participation in championship meets.  Motivational times help track an athlete’s improvement over time, relative to their peers.


This introductory post explains the essentials of USA-S times.  First we’ll explain the three different types of event times accepted by USA-S: long course meters (LCM),  short course meters (SCM), and short course yards (SCY). Next we’ll explain the difference between conforming, non-conforming, and converted qualifying times.

Three Event Time Units.

USA-S competition may occur in pools whose lengths are 50 meters, 25 meters, or 25 yards.  Official USA-S times are labeled by the pool length (“course”) in which they were achieved:  “L” for long course meters (LCM) or 50 meter lengths; “S” for short course meters (SCM) or 25 meter lengths; and “Y” for short course yards (SCY) or 25 yard lengths.  Meters are longer than yards, so times achieved in meters (LCM or SCM) are slower than those achieved in yards (SCY). And times achieved in shorter pools (SCM or SCY) are faster than those achieved in longer pools (LCM) due to the opportunity to gain speed at the wall during a turn.  SCM results are common in Europe but extremely rare in USA-S, so we removed them from our data set. SCY results account for 70% of our data, with LCM results accounting for the remaining 30%, with older athletes increasingly likely to swim LCM.

In prior posts, we’ve learned that the course has a significant effect on competition, including the likelihood of being disqualified, of dropping time, and of swimming faster in a relay.

Three Types of Qualifying Times.  

Events at championship meets typically have qualifying times.  To enter an event with a qualifying time, an athlete must have swum the event recently at least as fast as the qualifying time.  Each meet has a designated course (LCM/SCM/SCY). Some meets with qualifying times only accept times that were achieved in the same course as the meet; others may optionally accept non-conforming or converted times.


Conforming Time.  A conforming time is an official USA-S time that was achieved in the same course as the meet event.  So a LCM event time would be conforming for a LCM meet, but non-conforming for a SCY meet.


Non-conforming Time.  Meets that accept non-conforming times will provide multiple qualifying times for every event -- one for each type of qualifying time accepted by the meet.  So a LCM meet that accepts non-conforming SCM and SCY times will provide three qualifying times for every event -- one for the native LCM event and the other two for the equivalent non-conforming SCM and SCY events.  Athletes who qualify for an event via a non-conforming time will typically be seeded below athletes who qualify via a conforming time, according to USA-S Rule 207.11.7B, or they will be seeded using a converted time.


Converted Time.  Meets that accept converted times provide a mathematical formula to convert an official time achieved in one course into a qualifying time for a different course.  For example, the most widely used age group time conversion formula would convert a 50 yard SCY freestyle time of 25.00Y into a 50 meter SCM freestyle seed time of 27.755S or a 50 meter LCM freestyle seed time of 28.55L.  If a meet accepts converted times, achieving a 25:00Y in the 50 Free would potentially qualify the athlete for the 50 Free in three different courses: in a SCY event with a qualifying time of 25:00Y or greater, in a SCM event with a qualifying time of 27.75S or greater, and in a LCM event with a qualifying time of 28.55L or greater.


Age group athletes swim SCY events more than twice as often as LCM events.  As a result, we’ll see that accepting non-conforming or converted times can greatly increase the number of athletes who qualify for a championship event, particularly for LCM meets.