Marty Jertson is a PGA Professional and the Director of Product Development for Ping. Marty is credited with the design of many of the company's golf clubs, and is listed on over 125 patents. Marty joins On the Mark for a second time, and this time he addresses the many environmental factors that influence the distance of a golf shot. Whilst showing real-life examples from Major Championships and PGA TOUR events he elaborates on wind, temperature, lies of the golf ball incl. flyer lies in the rough and ball contact. Marty also talks about clubhead speed and ball-speed and how you can maximise those with club-fitting.