New Driver Head Adds 15 More Yards

Doing an outdoor fitting today with a gentleman we fit a couple of years ago into an R9 driver.  He was concerned that he was not getting as much distance as he felt he should and wondered if the new R11 S was any better.  Using the same shaft we fit him in and adjusting the weights to match his R9, we added 7.2 more yards in carry and 14.7 yards in total distance( 226.3 to 241.0).  Why?  The spin rate on the R11 S was 1300 rpm LESS and ball speed increased 1.4 mph.  We also worked on getting a more positive angle of attack as he was currently at -4.6 with his R9.  We moved that up to -2.7 which helped reduce spin as well.  Same shaft…better head and swing  = more distance.