Mik, bowly hole is a term I've heard before, so perhaps that is why it is open bowl, albeit I always refer to open hole. I live in the sticks and I use open hole, but cautiously. Some years I can lose two or three a day easily, so lock them in and let them out on occasions. Other times I am able to be on open hole all year round. Either the BOP are smarter some years or my pigeons are not as sharp, but I, as manager, must decide the tactics.