A pro doesnt necessarily shoot much smaller groups than your slightly better than average local shooters. The difference is they can do it for many many arrows in a row. A pro at lets say the stan open in p-burgh is going to shoot a 595 or better out of 600 possible. That is 20 arrows at 40, 20 arrows at 50, and 20 at 60, each worth 10 points or a 10X. Your X ring = 4.5 cm (less than 2"), and your 10 ring = 9 cm (3.5" approx). Tons of people can shoot a 3 arrow group at 50 yards that touch, but can you shoot that same 3 arrow group 20 times in a row within a 2" circle without dropping a single one? How about when there are a couple thousand people watching you and when there is a years salary on the line for you making that one single shot? That's the difference between better than average local shooters and the elite few pros that are out there.