A workmate of mine (serious golfer 5 h/cap) criticises me because i only use the indoor mats at the range. he is adamant that I should be outdoors on the grass. He swears by this and tells me that my h/cap wont fall unless I change from mats to grass. I dont particularly agree with him as I dont believe this theory. i am quite happy with my results. Anybody got any views on this argument?