From my observations at the US Open, I believe the pro's are THAT good for 3 reasons......
1. This is their living. As a result, they are at it all the time. If they aren't that good, then they don't last that long. There are plenty of "pro's" who aren't that good as witnessed by their VERY substandard performances on a dead flat condition.
2. They develop a mental toughness that has to be seen to be believed. The good pro's are very mentally attuned to the task at hand, again because they are oput there every week, having to adjust to different conditions, houses, climates, time zones etc.
3. They have the best available assistance at every tour stop with great coaches like John Jowdy, and the ball company reps who are in general very knowledgeable and can assist the players in equipment choices, setups and line decisions.
Having said that, I saw nothing at the US open to suggest that our top few players, with 6 to 12 months experience on tour, couldnt be competitive on the tour. It is a matterof a few minor changes to games and developing the mental toughness to deal with the weekly grind.