Each dog pulling a sled has a special role to play to maintain the team operating as one.
The lead dogs (in the 1st position) apply the musher’s commands, set the pace, and ensure correct direction. The swing dogs (in the 2nd position) ensure the team follows turns. The team dogs (in the 3rd position) pull the sled and help maintain speed. The wheel dogs (in the last position) pull the most weight of the sled and therefore, tend to be the strongest within the team.