When you hit a golf ball it spins in reverse on its axis. If that axis is horizontal, the ball goes straight. Tilt the axis right or left, and the ball will slice or hook. The BirdieBall is about half the weight of a golf ball, but its non-aerodynamic shape before it’s hit, causes you to feel resistance on the club head-this makes it feel like a golf ball on impact. You’ll know you’ve made good contact by the gratifying sound and feel after a pure strike!