I’ve settled on a broken wrist or low wrist position. I’ve been shooting a lot the last few days trying different things. Once the wrist muscles get tired you almost have to relax into the most bone-on-bone position to hold the bow arm straight and true.
I’ve been devouring archery books and so far the best two are:
“Instinctive Archery Insights” by Jay Kidwell and “Core Archery” by Larry Wise. Both complement each IMHO. Kidwell really simplifies the whole shooting process into the essentials and gives you a mental framework for creating a successful inner mind shot process. Very good. I’m still reading Wise’s book but he’s great at body mechanics and had the best section on hand position and “why” there is a right way and a worse way. I had always wondered what was going on when I grew tired and started slapping by forearm with the string…. it was my hand position. Now I have a good “ideal grip” that I am repeating to imprint into my medulla and one that is putting arrows where I am concentrating.
In the end, I think a lot depends upon the grip of the bow. Most longbows I have seen have a more vertical grip whereas target bows, compounds and recurves tend to have deeper grips that allow a more straight wrist.