The One Iron Golf System was developed by David Lake around the concept that playing better golf relies on clubs of the same length, rather than clubs of varying lengths. Lake published a book in 1998 touting the system, and his company manufactures single-length golf clubs for anyone.
Lake's research determined a golf ball is harder to hit accurately when a club is longer. The difficulty with single-length clubs is that a set must be custom-fit for one person, because players of different heights and arm lengths need different club lengths. Instead, club manufacturers opt to make clubs of different lengths, so players adjust their stances for each iron because this method is cheaper.