It's basic geometry-- circumference of a circle increases by pi times increase in radius, which in this case is the width of the horse, which in turn is a little less than a third of the length of a horse. So it costs 1 length for every added path (horse) off the rail, regardless of distance. But what a length is worth in points varies with distance from 1 point = about 1 length at 5f, to 1 point = about 2 points at 1 1/4 miles.



TGJB