Lanny Bassham, Olympic gold-medalist in small-bore rifle competition, tells what concentration does for his marksmanship: "Our sport is controlled non-movement. We are shooting from 50 meters over half a football field at a bull's eye three- quarters the size of a dime. If the angle of error at the point of the barrel is more than .005 of a millimeter (that is five one-thousandths), you drop into the next circle and lose a point. So we have to learn how to make everything stop. I stop my breathing. I stop my digestion by not eating for 12 hours before the competition. I train by running to keep my pulse around 60, so I have a full second between beats I have gotten it lower, but found that the stroke-volume increased so much that each beat really jolted me. You do all of this and you have the technical control. But you have to have some years of experience in reading conditions: the wind, the mirage. That's 20% of your problems. You then have the other 80%, the mind.