The Fibonacci suite is an arithmetical succession of natural numbers such that (i) the first two are 0 and 1, (ii) each term following 1 is the sum of the two previous ones. Hence it goes like 0,1,1,2,3,5,8,13,21,… So the idea is to cut out of the sequence a series of numbers that will give the proportions for the leader: 1,2,3,5,8,13. So for example it would give 5,10,15,25,40,65 inches. Then comes the question of the diameter. The original author gives a formula (start FOR EXAMPLE with .45 then proceed taking a half and multiplying by the golden proportion, which is a clear case of delusional numerology) that nevertheless gives a reasonable series: .45 – .35 – .30 – .25 – .20 – .16 – .12
For those of you stuck with the imperial obscurities, I’m sorry. I can do inches, but I struggle with Xes, so diameters are in millimeters, like they should in a rational world. ^_^
I’ve used the formula and it worked well for fishing wets with a 4wt. Only, I’m too sloppy to make all these precise measures when I’m tying a leader, and since I do a lot of tailing loops, especially when lawn training, I destroy lots of leaders, so I tie them not infrequently, and I really don’t bother with precise measuring. I just go for decreasing.
But if you want to impress the crowd with arcane details and esoteric theories, that Fibonacci stuff is good.