<P> In the 16th and 17th centuries the word was applied to horse - dealers, postilions, itinerant minstrels and vagabonds, and thus frequently bore the meaning of a cunning trickster, a "sharp", whence the verb to jockey, "to outwit", or "to do" a person out of something . The current usage which means a person who rides a horse in races was first seen in 1670 . </P> <P> Another possible origin is the Gaelic word eachaidhe, a "horseman", (pronounced YACH - ee - yuh in late medieval times, with the ch pronounced as in German). The Irish name "Eochaid" (YO - ked) is related to "each" (yek), horse, and is usually translated as "horse rider". This is phonetically very similar to "jockey" </P> <P> Jockeys must be light to ride at the weights which are assigned to their mounts . There are horse carrying weight limits, that are set by racing authorities . The Kentucky Derby, for example, has a weight limit of 126 lb (57 kg) including the jockey's equipment . The weight of a jockey usually ranges from 108 to 118 lb (49 to 54 kg). Despite their light weight, they must be able to control a horse that is moving at 40 mph (64 km / h) and weighs 1,200 lb (540 kg). Though there is no height limit for jockeys, they are usually fairly short due to the weight limits . Jockeys typically stand around 4 ft 10 in (147 cm) to 5 ft 6 in (168 cm). </P> <P> Jockeys are normally self employed, nominated by horse trainers to ride their horses in races, for a fee (which is paid regardless of the prize money the horse earns for a race) and a percentage of the purse winnings . In Australia, employment of apprentice jockeys is in terms of indenture to a master (a trainer); and there is a clear employee - employer relationship . When an apprentice jockey finishes their apprenticeship and becomes a "fully fledged jockey", the nature of their employment and insurance requirements change because they are regarded as "freelance", like contractors . Jockeys often cease their riding careers to take up other employment in racing, usually as trainers . In this way the apprenticeship system serves to induct young people into racing employment . </P>

Average height and weight of kentucky derby jockey
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