When considering lofts on drivers, we always have to assume square at impact. So, if the designed loft is 10 deg. and the designed face angle is 1/2 deg. open, the effective loft is 9.5 degrees. If the designed loft is 10 deg. and the designed club face angle is 1 degree closed, the effective loft is 11 degrees. Effective loft is the “loft at impact assuming the club face is square to the target line”. We always have to assume the club face is square at impact when discussing the relationship of club face and loft.