hi Go Navy
last year tiger was playing clubs and balls that had not even been released on the market. prototype balls and clubs and i believe he had been involved in some of the research. i don't know if was just him trying out different club head and shafts on the range and then using what felt good on the course.
his irons and wedges are listed as Titleist forged muscleback prototypes. and last year he had a protatype ball but it now listed as a pro90.
cheers
bill