Thanks Brad, very helpful. I came across a story prior to the 2001 U.S. Open at Southern Hills discussing the USGA's decision to step away from the tradition of brutally deep rough beginning with the '99 Open at Pinehurst due to No. 2's turtleback greens and continuing this "more playable" rough through Southern Hills in '01.
Did this trend continue through the '05 return to No. 2? through the remainder of the 2000s?