So if the elbow comes up it's a right hook or overhand, If elbow stays down it's a straight right hand..? I mean obviously the punch still turns over at the end but in a much more linear compact fashion..

Also some people refer to a looping right hand but I guess that could be a hook or an overhand.

For it to be an overhand would it have to come over the top of the guard as opposed to around the side of the guard across the v in the opponents arm..?

Or is it more to do with the mechanics of the punch rather than the intended target..?