I played Torrey Pines South last March. We had to walk the course because they were getting it ready for The Buick and Open then. We played what I call regular tees and the course was still close to 7000 and the rough was unreal. We were given flags to mark our balls because you could find it, then go get a club and lose it.
Now imagine that times 10 for the Open.
That course is brutal. We also played the first 5 holes in rain with a strong wind. That made it even harder.
I normally shoot in the low 80's, sometimes high 70's on an easier course and mid to upper 80's on the longer courses. Well I shot a legitimate 98 that day and felt like I shot a 75. The course was that challenging.