A coach or infield leader will yell double cut.  Double cuts are needed when a ball is hit to the fence and there is gonna be a long throw to a base.  On a ball hit down the left field line and an expected play at 3rd.  The SS will be the lead relay guy and 2B will be the trail man.  The pitcher will need to back up 3rd base.  1B will follow behind the the runner as they run to 2nd and then the 1B will be the coverage at 2nd.