A "Stretch" call must have two groups of four doing the call, then two dancers from each group of four "stretch" past the line dividing the two groups to end on the other side.
Horseshoe Turn requires 4 Outsides and 2 or more Centers -- Horseshoe Turn is generally an 8-dancer call. An 8-dancer call can not be "Stretch"-ed.
Ceder Chest Definition of Stretch
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