what control does in Mastercam is allow you to input the entire radius of the cutter in the CNC control diameter offset page. using control makes it a lot easier when you want to manually edit your program at the cnc control because your positions in the g code program will match the numbers on the print. the disadvantage if if forget to enter the radius of the cutter in the cnc control diameter offset page you will more often than not scrap the part, were as with wear you have a much better chance of not scraping the part. make a simple rectangle. contour it using control. post the program and compare the numbers to your print. do the same thing and use wear and computer and compare.