To stretch into a string, fold into one with your leg - that is exactly what you need to do in order to perform a standing split.
This what the element is called what a gymnast, standing on one leg, catches the other from the back.
The fundamental difference between the standing split and the ring elements is the straight back leg. The athlete can hold it with one or two hands.
The rules call the element the “back split with assistance” and it can be performed as a balance (on a full foot or on a relevé) or as a rotation (only on a relevé).
The balance in form of a standing split is rarely seen by itself, because it isn’t worth a lot of points. The so-called cost of a rotation is dependent on the number of turns, so the position of the “string” in a sense helps, because there is less resistance with air, and the rotation is faster.
This rotation into a side split is often called the the signature element of the Alina festival participants- the Averin sisters, their 3-4 quick rotations look easy and effortless.
The standing split can be called one of the basic positions of the gymnast's body in the element, when combined with others, it becomes part of a more complex and expensive element. For example the Gizikova - transferring the leg from the front split with the help to the standing split positio), Kapranova (transition from the front split to the tightening position through a turn body) and others.