Pursuit tc420 driver introduced the slot sole to the titanium driver market. The driving force behind the engineering was the idea that casting a deep groove into the sole would provide a mechanism that acts like a loaded hinge and propels the ball off the face at a greater velocity. At that time, several equipment manufacturers were adding a channel to the crown. Our experience told us that most golfers miss the sweet spot toward the sole of the club. Putting the slot on the sole seemed logical. The idea worked so well that the tc420 exceeds the USGA's COR limits.