Via Engadget:
If you can't golf, you're going to suck at OptiShot's sim. That's because you take full-blooded hacks at a ball with a real driver, iron or putter, and not a gamepad or mouse as with, say, EA's PGA Tour series. The swinging mat has two strips of 16 infrared sensors that detect when your club zips through the ball before, during and after contact. It measures your clubhead speed to within plus or minus 2 MPH, and the face angle and swing path to within 1.5 and 1.9 degrees, respectively. The sim then figures out the distance your ball would travel in real life and whether it'd hook, slice or go straight.