Titleist PT. The classically-shaped Titleist PT (Pro Trajectory) was used by Tiger Woods during his Grand Slam winning season. Resultant demand for the club was so high Titleist had to re-release it - which they did as a thru-bore version. This is the Original as used by Tiger. Titleist Pro Trajectory Metals are designed to meet the needs of serious golfers by combining traditional shapes with superior performance characteristics. Essential to the concept of the PTM is the 15" radius horizontal bulge on the clubface. The purpose of this is to compensate for off-centre hits. A club without bulge imparts sidespin on the ball causing the ball to spin away from target. The bulge on the PT creates opposite side spin on the ball so the ball is brought back toward the target.