Pretty classic exchange, I hope Marcel never comes back. I read his ebook. I have also spent time with aimpoint, I have the digital level, the charts and I putt on my intended line. Marcel's system is better, faster and creates a more true and deeper knowledge of the subject. I am not as good a golfer as you iacas, but I took the time to read and understand his system, you bang on about parabolas being irrelevant but you fail to understand that it is sections on a parabola...