The Classic 1.5 combines the Classic 1 head with a short semi-offset neck that creates more toe-flow, closing the putter head at impact. Scotty likens this to a swinging gate, closing square at impact. Since Scotty had just started his company and R and D capital was limited, he would take the head of the Classic 1 and weld necks as prototypes to determine the best toe hang, offset and setup. Once a prototype was refined it would go into production as an all milled, one piece Classic collection putter made from a billet of 1018 cold-drawn carbon steel. If you are fortunate enough to come across an early 1.5 prototype, check to see if the neck was welded and you just may have an early tour model. The 1.5 was then renamed the Santa Fe as Titleist and Scotty joined forces.