Butterfly stroke

Entry and stretch

The entry and stretch begins when the arms enter the water above the head. The arms should enter straight or with the elbows slightly bent, about shoulder-width apart, and with the thumbs pointing downward so that the hands can slice into the water.^[11][12] The downbeat of the first kick should occur around the same time as the arms enter the water.^{[note 1]}

This leg downbeat occurs at the end of a wave like motion initiated by the upper body travelling downward at the end of the recovery.^[12] The swimmer faces downwards on entry to minimise the hydrodynamic drag on their head and allow the head to initiate the wave.^[15][16] Greater smoothness on entry contributes to increased forward acceleration from the kick.^[16]

Swimmers may glide for a short period of time in a streamlined position after completing the downbeat of the first kick and before starting the outsweep and catch.^[17][18]

Outsweep and catch

The purpose of the outsweep is to position the arms in such a way as to maximise the propulsion from the insweep that follows. The catch occurs towards the end of the outsweep and is the position from which the swimmer transitions to the insweep.^[19]

During the outsweep, the hands sweep outward and rotate and the elbows bend, such that by the end of the outsweep, the arms are further than shoulder-width apart and the whole of each arm is facing backwards against the water. Throughout the outsweep, the arms decelerate so that they are moving slowly during the catch before accelerating during the insweep.^[19]

The movement of the outsweep, the upbeat of the second kick, and the buoyancy force from the upper body all work to cause the upper body to begin to rise.^[20] During this phase, the head also begins to lift.^[19]

Higher-skilled butterfly swimmers travel further per stroke and exhibit greater synchronisation between the arms and legs at various points throughout each stroke cycle.^{[note 2][21]} Greater speed variation within each cycle is also associated with less efficiency.^[22]

Origins of the butterfly kick

The International Swimming Hall of Fame attributed the earliest mention of the butterfly kick to George Corsan, who introduced it by demonstration to David Armbruster in 1911, calling it the "fishtail kick".^{[note 3][25]} Another discovery of the butterfly kick was made by Jack Sieg, who, while being watched by Armbruster, went underwater, lay on his side, and performed the butterfly kick in imitation of a fish.^[26][27][28] Sieg and Armbruster further experimented with the kick until Sieg was able to beat the best flutter kickers at the University of Iowa using it.^[28]

Armbruster and Sieg experimented with using the butterfly kick in breaststroke and had excellent results. Presumably to reflect this, he also began referring to the previously named "fishtail kick" as the "dolphin breaststroke kick".^[29] He published his results in 1935 in an article called "The Dolphin Breast Stroke" in The Journal of Health and Physical Education^[28] where, due to its potential to be faster than the traditional whip kick, Armbruster was enthusiastic to have it legalized within the breaststroke rules, to "offer this new type of stroke for exploitation as a competitive racing-speed stroke".^[28] Armbruster followed this appeal with another longer article in the 1937 NCAA Swimming and Diving Guide called "The New Dolphin Breast Stroke on Trial", which further urged the NCAA to allow the kick in the rules for the extra speed.^[30] Unfortunately for Armbruster, this would not come to fruition, as in a FINA meeting in October 1938, the bureau unanimously agreed to prohibit up-and-down movements of the legs in the vertical plane.^[31]

Origins of the butterfly arm

Prior to 1935, the breaststroke rules from both FINA and the NCAA stated that the arms had to be simultaneously pushed forward on recovery.^[32] Since the rules did not state that the arm recovery had to be underwater, a few swimmers came up with the idea of an overarm recovery, which was initially called the "flying fish".^[33] The International Swimming Hall of Fame credits Sydney Cavill with creating the overarm recovery,^[34] but it is also possible that Erich Rademacher independently discovered it in 1927 Germany. Rademacher generally used the flying fish coming out of the turns,^[35] which was dubbed the "flying breaststroke turn" and at the end of the race, which was dubbed the "flying finish".^[36]

Rademacher insisted that this did not break the rules, and continued to use it in the late 1920s and early 1930s in the US.^[37] Sources conflict as to whether he used it in the 1928 Olympics, with the International Swimming Hall of Fame saying he did^[35] but Francois Oppenheim's book "The History of Swimming" saying he didn't.^[38] In 1935, presumably for the removal of ambiguity, the NCAA changed the rule regarding the breaststroke recovery to use the word "moved", rather than "pushed".^[39] Other early adoptees of the "flying breaststroke turn" were Walter Spence and then Wallace Spence, who went on to dominate the breaststroke events using it.^[40] The next notable swimmer to further innovate on the butterfly arms was Henry Myers, who in early December 1933 used the flying fish for the whole of the breaststroke leg of a three-stroke medley head, winning against Wallace Spence in spectacular fashion.^[41] The reaction to this performance was mixed. Though the officials did not disqualify him, the Brooklyn Central YMCA's magazine wrote a "vitriolic article" that made disparaging remarks about "the sportsmanship of young Myers who observed the letter but not the spirit of the breaststroke rules".^[42] Furthermore, Wallace Spence withdrew from the finals of the event alleging that Myers was swimming freestyle and he should "learn how to swim breaststroke properly".^[43] Despite this, Myers was very proud of his creation, saying: "It [is] uninteresting to watch a breaststroke race, in time, the old breaststroke would have become as passe as the English sidestroke, as far as racing is concerned. A butterfly-breaststroke race is a very exciting race to watch. The splashing and violent arm-motion seems to be quite conducive to spectator enthusiasm."^[43] Myers interested two teammates of his: Lester Kaplan and Paul Friesel, in the overarm recovery. Kaplan and Friesel went on to set new personal bests in breaststroke by over 3 seconds using it.^[43]

As the overarm recovery caught on more, a swimmer called John Herbert Higgins, in February 1936 at the 1936 National AAU Indoor Swimming Championships swam a time of 1:10.8 for the 100 metre breaststroke event, and became the first swimmer to set a world record using exclusively the flying fish.^[44] This technique of continuous flying fish would come to be known as "butterfly-breaststroke". Later at the 1936 US Olympic Trials, Higgins set a new 200 metre American Record of 2:44.1.^[45] In the 1936 Berlin Olympic 200m breaststroke finals, Higgins finished fourth while using the butterfly-breaststroke technique.^[46][47] Though the butterfly-breaststroke was gaining traction, it was almost prohibited as a style of breaststroke in an October 1938 FINA Executive Bureau meeting where it was "supported by four votes out of seven to prohibit the butterfly arm recovery in the breaststroke event. However, since alterations to the technical rules required a two-thirds majority before adoption, the motion was declared not carried".^[31] In the 1948 London Olympics, all but one of the finalists used the butterfly-breaststroke technique, and the only finalist who did not use it (Bob Bonte of the Netherlands) finished last.^[48]

This dominant display of butterfly-breaststroke led to the idea of separating breaststroke into two breaststroke events, consisting of traditional breaststroke and butterfly-breaststroke.^[49] However, the IOC president Sigfrid Edstrom decided not to add any events to the 1952 Helsinki Olympics, due to the chaotic situation after World War II.^[50] Despite this, FINA did add a definition of the two styles of breaststroke to the rules which named traditional breaststroke style "A" and butterfly-breaststroke style "B". A consequence of this was competitors were not able to swim both of the styles in the same race.^[51]

Origins of the full butterfly stroke

By 1952, the argument for separating the "A" and "B" styles of breaststroke was gaining momentum,^[52] and hence in 1953, breaststroke was separated into two different events. Furthermore, while traditional breaststroke required the whip kick, the new butterfly stroke allowed the use of butterfly kick. Now the butterfly stroke was its own separate event.^[53] The butterfly stroke was first seen in the Olympics at the 1956 games, where the Men's 200 metre butterfly event was won by William Yorzyk, and the Women's 100 metre Butterfly event was won by Shelley Mann.^[54]

Men

Women