"In 1994, at the age of 30, Paul Goydos's driving average was 258 yards. That year only two golfers averaged drives of 280 yards or better. In 2004, at the age of 40, Goydos's driving average was 280 yards off the tee, ranking him 153rd in driving."
In 1994 I was playing a Burner Bubble driver. 43.5 inches/8.5 degrees. I hit the sweetest, consistent, low draw with it.
In 1997, I was using a 9 degree Warbird, and sometimes, a 7.5 degree GB Bertha. Same shot patter, but the GBB was 7-8 yards
longer, with a bit less control. (also 43.5 inches in warbird...44 on GBB)
Was injured in '97, came back to play in 2000. Was using a Bridgestone, 10 degree driver/44.5 inches, and took 2 months to relearn
to launch the ball just over 11 degrees (instead of 9.5 with way more spin).
The fitting ideals had changed to a completely different optimum while I was hurt. In my first session, I picked up nearly 10 yards,
simply by changing to more loft and dropping my spin rates. The flight was 100% different than what I played.
I was using the highest spin ball available (Bridgestone), changed my swing a bit to reach a new optimum.
Paul did a lot of the same process, though I believe it was with a Titleist driver and ball.
Research keeps leading to new optimums and better marriage of ball and club. As players, adjustments are also made to launch it correctly to meet the optimums.