The mean score is 60 out of 100 and the standard deviation (in other words, the variation in the scores) is 15 marks (see our statistical guides, Measures of Central Tendency and Standard Deviation, for more information about the mean and standard deviation).
What Are the Six Different Types of Swimming Strokes? Swimming provides all-around, low-impact body conditioning as well as exciting competition. Competitive swim meets allow only four strokes -- butterfly, backstroke, breaststroke and the crawl. Two other strokes -- elementary backstroke and sidestroke -- contribute to swimming longer distances, as different sets of muscles are used. The fastest stroke for most swimmers is the front crawl.
World record progression 100 metres backstroke. Main article: List of world records in swimming. This is a history of the 100 m backstroke world record as swum in both long-course (50 m; Olympic) pools and short-course (25 m) poolsâthe two categories recognized/tracked by FINA. Graphic data for World Record Progression in Men and Women Swimming 50m-100m-200m Long and Short Course Butterfly-Backstroke-Breaststroke-Freestyle.