At all clubhead speeds, the maximum driving distance was achieved with a positive angle of attack. In other words, hitting up with the driver produced the longest drives! This is contrary to the proper technique to hit irons and fairway woods where the clubhead should impact the ball with a descending blow or "Hit Down on the Ball".
According to Fredrik Tuxen, the inventor of the TrackMan launch monitor system:
Optimizing driving distance is a question of high ball speed, high launch angle and low spin rate. But you can, in general, not increase your launch angle without also increasing the spin rate. So the fundamental question was: What determines what spin rate/launch angle combination can be obtained? It turns out that for a well hit shot, attack angle is the primary parameter dictating what combinations of launch angle /spin rate are obtainable for a given player.
Attack angle is the primary parameter telling you why you obtain certain combinations of launch angle and spin rate – it is even more important than the club head speed! Also, the attack angle is related almost solely to your golf swing and not equipment related, which means it is something you, as a golfer, can change – it is pure technique!
Players like Tiger Woods, Phil Mickelson, Sergio Garcia and Charles Howell III are all players who often swing with significant, negative attack angles. However, common for this group of players is their very high club and ball speeds, so they fly the ball pretty far despite their negative attack angle – they do not really have a distance problem! However, if they increased their attack angle they could hit the ball 30-40 yards further. But apparently they have deliberately chosen not to do this.
