Many jumpers find building round or star formations to be difficult.
There are several ways to build rounds. Jumpers can form lines and then dock these pieces together to form a round. Jumpers can fly no-contact at a predetermined distance from a small base round, and then pick up grips when all jumpers are in position. The star is such a unique formation that it is possible to build the formation so that no one is in their correct slot until the last jumper docks. No other formation can be built like that.