Many phrases have originated as jargon in the world of sport, including several from boxing. The memory of Muhammad Ali dancing round the ring with his hands at his side and going on to win the bout might encourage us to think that is the origin of this one. Not quite, although it does come from sport – 19th century horse racing. Jockeys need to keep a tight rein in order to encourage their horse to run. To win "hands down" is when a horse was so far ahead as to be certain of winning, the jockey could stop urging his horse to run faster – thus lowering his hands and relaxing his hold on the reins. In the early 20th century, the phrase began to be used in a figurative sense, to denote an easy win.