MMmm think I should of had a bet here ::) The unregistered hybridised Alaskan husky is preferred for dogsled racing. It is primarily used for working purposes, unlike the Siberian Husky who is used for both show and working purposes. Alaskan Huskies are carefully bred to produce the best working dogs possible. The breeding of the Alaskan Husky are planned breedings and are technically pedigreed, however they are not consider pure and are not registered by the AKC or CKC because they are sometimes crossed with other Northern and non-Northern breeds to produce the best working dogs possible. Unlike the Siberian Husky who is a purebred dog who is registered with the AKC and the CKC and is used as a showdog as well as a working dog.
In sled pulling races the Alaskan Huskies are usually used in the longer distance races and Siberian Huskies are often used in the shorter distance races. Sled dogs have been known to travel over 100 miles in a 24 hour period.