A scratch player playing from the back tees on a PGA Tour setup would shoot 4-5 strokes higher than the same player on the same course from the same tees without the PGA Tour manipulations. It's true there probably would be some benefit from the pristine playing surfaces, especially now that repairing spike marks is allowed.
But the comments on this thread re:the depth of the rough on tour are way off mark. Even an extra inch of bermuda rough at an average course like CC of Jackson presents enormous difficulties for a scratch player. The rough during tournament week at places like Muirfield Village, Bay Hill and PGA National is hard to describe. Not just the height but the "stickyness". Combine it with tightly groomed runoffs, shaved banks around water hazards, and the relentless demands of any 7,500 yard golf course, and scoring will quickly snowball for all but the very top players in the world. The bottom line is that the top 1,000 players in the world are just really really good in all phases of the game.
Everyone understands just how far the ball is traveling today, because it's easily measured and documented. But what's underappreciated is just how good the short games and recovery shots are of the games elite. Tolerances on balls, shafts, grooves etc are more consistent than ever before. Wedges are replaced every 3 weeks. Teaching methods are better. Training methods are better. Everything is aligned to create more elite players.
There are no easy answers. And the idea that courses aren't set up hard enough is just going down the wrong path.
My comments are based on walking inside the ropes during tournament weeks of Web, PGA Tour and major championships for the past 15 years.
Michael Wolf