 Although fast acceleration ("a turn of foot") is usually required to win either type of race, in general sprints are seen as a test of speed, while long-distance races are seen as a test of stamina.The most prestigious flat races in the world, such as the Prix de l'Arc de Triomphe, Melbourne Cup, Japan Cup, Epsom Derby, Kentucky Derby and Dubai World Cup, are run over distances in the middle of this range and are seen as tests of both speed and stamina to some extent.In the most prestigious races, horses are generally allocated the same weight to carry for fairness, with allowances given to younger horses and female horses running against males.