The ponies are 14.2 to 16 hands (1 hand equals 4 inches or 10.16 centimetres). They weigh between 900 and 1100lbs-pounds- (about 408 and 499 kilos). Ponies can be ridden to play from the age of 5 up to 18 or even 20 years old sometimes. Polo ponies are not actually ponies because they are full-sized horses. Thoroughbreds are a common horse breed to use as polo ponies because they are fast and agile.