What is a handicap race?

In horse racing, Flat or National Hunt, a handicap race is a race in which each horse carries a weight determined by its official rating, so that, at least in theory, every horse has an equal chance of winning. To be eligible to run in a handicap, a horse must qualify for an official rating and, to do so, must usually run in three non-handicap, or weight-for-age, races, so that the British Horseracing Authority (BHA) handicapper has the opportunity to assess its level of ability. The official rating of each horse corresponds to its ability, expressed in Avoirdupois pounds, in the eyes of the handicapper. In a handicap race, the horse with the highest official rating carries the heaviest, or ‘top’, weight, while the other horses carry less weight, proportionate to their official ratings. Of course, the official rating of a horse can go up, down or stay the same, depending on how it performs from one race to the next.