The concept didn't start with F-Class. I'll tell you that. It's simply just a logical concept. If every projectile travels at the exact same speed, vertical dispersion can be mitigated. If you're still seeing vertical on target, it's something else. Likely OBT.
It is definitely a simple to understand concept... unfortunately, the system it is applied to is anything but simple. And that understanding is very old... like early 1900's type old.
The interest in trying to tune using ES/SD definitely grew with the growth in LR F class AND the improvements in chronographs. Unfortunately, these chronographs were no where near as good as what you can get easily today but things like the Oehlers were available to a few.
Going from large double digits ES/SD values to small double digits saw a massive improvement in LR precision... so much so, F class cut their target sizes in half.
That started the quest to see if even lower values would gain even more precision. Outside neck turning, annealing, milligram scales... and of course, better understanding of ignition, case volumes, powders and charges, etc, etc.
SR primer brass... old concept, rebooted in F TR a number of years back.
The improvements continued to increase especially when better quality higher BC bullets started to become the norm. Things got better and better and then they plateaued a number of years back.
Some of us started seeing problems with the absolute lowest ES/SD's when applied to targets downrange... in fact, some of the WORST performing loads had the smallest numbers.
As a reloading and LR techie, I am all over any concept that can improve my performance but any process has to be 100% reliable and repeatable.
So back to my last challenge.... demonstrate that single digit ES/SD will ALWAYS produce the best results on target downrange.
Spoiler alert, we already have posts where shooters are wondering why this isn't working.... and one even has some really nice data and documentation proving my point.
A theory is only good until you run into an exception... maybe one is no biggie but when you start to see a decent percentage contradicting the theory, maybe the theory isn't so good?
But don't let this stop you using any method you see fit. If the performance downrange is what you want and expect, it is all good.
Jerry