Apprentice jockeys are given a weight allowance over journeyman jockeys. This means that a horse ridden by an apprentice is allowed to carry less weight in a race. Extra weight generally slows a horse down, so a horse carrying less weight may have an advantage over one carrying more. However, this allowance may be offset by the skill of a more experienced rider. So a trainer has to choose between having a heavier, more experienced jockey, or a lighter but less experienced jockey, depending upon what is right for the horse.