Might I add that the ball takes off perpendicular to the club face angle when the ball leaves it. The club path imparts spin to the ball as it "rubs" for lack of a better word the back of the ball. If the club head moves straight through the center line of the ball, only straight backspin will be produced (unless the club head is moving upward through impact). But when the club head comes into impact to either side of the ball's center, sidespin is produced. So to hit a straight shot at the target, the club face has to be aiming at the target and the path has to move straight through the center of the ball toward the target. But you can hit a straight push if the club face is aimed to the right of the target and the path is moving equally to the right. So straight shots = club face square to path. Curved shots = club face not square to path. For example, if the club face is 2 degrees open, but the path is 4 degrees inside out, the ball will start 2 degrees right of center and curve back to the left of center.
I've always believed that due to compression, the ball would have to take off in the direction in which it was compressed and that the club face angle relative to the path caused the curve. I had it half right. Live and learn.
This seemingly contradictory info is important to understand because better golfers often waste time fixing the wrong aspect and can actually worsen the problem.
Does anybody have hard numbers on the path to face interaction?
JD