Quote Originally Posted by hoglahoo View Post
I'm not familiar with progressive beard reduction theory - please, point me in the right direction or give me the cliff notes version? Others may share this question as an introductory toward understanding the difference between this and shaving it all off in one pass
Cliff notes is you perform mutliple light passes in the different directions. Each pass reduces the whisker some nominal amount. This allows you to get a shave as close as possible with the minimal amount od irritation.

Somebody stated that the reason this works with a single edge blade and not say a M3 is because of how the multiple passes in different directions shapes the end of the whisker. With a single blade, at the end, the whisker is shaped like a pencil tip, which feels softer/smoohter longer. With an M3, no matter which direction you shave or how many passes you take, the end of the whisker is shaped like a blunt chisel.

I'm not sure if that answers your question, but that's the best I got. : - )