Horse pulling is a draft horse competition where horses in harness, usually two animals, pull a stone-boat or weighted sled and the winner is the team or animal that can pull the most weight for a short distance. There are different weight classes and strict rules to avoid animal cruelty. Draft breeds are commonly used, but there are also competitions for ponies, where they pull weights relative to their size, and usually for shorter distances than full-sized horses. Similar sports are tractor pulling and the dog sport of weight pulling.