Closed,Shut,Hooded Clubface

[mp33]

I understand that if you have a problem with your swing you might need to change the clubface first.Now I have played and watched alot of golf and I have noticed a greater percentage of golfers with a severely shut clubface at the top then open.I would even say 85-90% and usually they slice the ball.
Nick Faldo says you can play pretty good golf with a open or square clubface but it becomes harder when the clubface is closed.
What does TGM think about this and how do you correct it? I think closed club you better not horizontal hinge but use angled.