Climb On Closed Systems

The best practice in any kind of climbing involving a rope is to climb on closed systems. Either tie the belayer in to the bottom end of the rope, or put a stopper knot near the bottom end of the climbing rope. Doing so ensures that the climbing team never encounters a scenario where the bottom end of the rope passes through the belay device putting the climbing party in danger.

Check out this article from Accidents in North American Climbing from the American Alpine Club

Ryan Cavender