Everyone knows that you should try to hit the ball in the center of your iron — that's where the sweet spot is. Strangely, however, that's not the center of gravity. At least, not unless you're playing with a set of Nike Vapor Irons. Developed with input from Tiger Woods, Modern Muscle weighting technology moves the CG to the center of the iron, resulting in more solid hits and improved flight. The Vapor Pro uses it to provide maximum performance, while the Pro Combo uses it — along with a RZN insert — to provide blade-like workability with the power of a distance iron. And for the rest of us, there's the Vapor Speed, which combines the tech with FlyBeam-reinforced hollow cavities in the long irons for maximum forgiveness. We hit all three sets last night over a couple hours, and can't wait to get them on the course. We also asked Tiger for some pointers, but he just laughed, shook his head, and walked away.