Before self-tailing winches, a sheet was always cleated off after winding it in. Many of today’s yachts don’t have sheet cleats, leaving no choice but to rely on the self-tailing jaws. This is all very well until someone tumbles against a winch where the jaws weren’t completely clamped into the ropework. The sheet is knocked out and away it goes. Nasty. This will never happen if you flick an extra turn around the winch after you have finished winding. It can be as slack as you like, because its purpose is merely to guard against the unforeseen. If Clumsy Cuthbert catches his boot in it and unwinds it, the only result will be the loss of a turn that is doing nothing anyway.