To learn to walk lines accurately, use a measuring tape to mark a distance of 12 feet in your arena at home and teach yourself to cover 3 feet with each step so that you walk the measured distance in four steps—that’s one horse stride. When you walk your courses, stand at the landing side of the first jump of each line with your back to it and your heels against its base, then count your steps to the center and base of the next jump, noting the number of strides with each fourth step: “One, two, three, ONE [stride], one, two, three, TWO, one, two, three, THREE.” Subtract one stride to account for takeoff and landing.…