The Attack Angle: How It Works
To maximize your drives, you need to hit the ball on the upswing, because this increases your launch angle without adding clubhead loft. You'll also produce less spin while increasing the force with which you hit the ball. "I had been a low-launch, low-trajectory player, and when I changed to a positive angle of attack, I picked up 20-plus yards," PGA Tour pro Jeff Sluman said. "You'll be taken aback by how simple this change is."
When you hit down on the ball, even as little as 5 degrees, you have virtually no chance with a standard driver to achieve the launch angle and spin rate required for max distance, which for a 90 mph swing is 10 degrees of launch and 3,100 rpm of spin. (To get these numbers with a minus-5-degree swing, you'd need a 15-degree driver!)