Minombre- I agree that the butterfly stoke is difficult, but not for Michael Phelps. In fact, that is his signature stroke.
The reason is that when Michael Phelps starting swimming at the age of 9, he did not want to put his face in the water, so his coach had him swim on his back and work on the butterfly stroke instead.
Coach Bowman, Michael Phelps’ coach suggests that swimmers wanting to perfect their butterfly stoke extend their arms when they swim as much as possible. He adds that the long strokes help the swimmer develop speed.
According to Coach Bowman, the average swimmer takes twelve to sixteen strokes to cover 25 yards, while Michael Phelps does it in six to eight strokes.
Cross training the upper body with weights and a medicine ball are also suggestions that the Coach Bowman recommends.