Results from hundreds of player and robot tests at PING offer overwhelming scientific support for the effectiveness of fitting for stroke. In recent years more diagnostic tools and testing equipment have become available, and the results prove that a golfer’s consistency improves when their putter balance matches their stroke type. It was interesting to observe that golfers putt more consistently with stroke-appropriate models, but they also show a personal preference for these models, too. Prior to putting with them, golfers are drawn to models that fit their eye, even before they fit their stroke.