What NH said ! Thats it exactly , for spanning (or central spanning beams) braces are strongest if the mort. for the brace is centered in the post. I've run it in a lot of old buildings, braces centered. Curved braces sound cool. I did curved braces on several projects. I use dovetails for bracing whenever I can. I would not recommend them for most softwood apl., I use larch almost exclusivly for frames.