Why the 40° edge will not score as well as the 20°

[grepper]

Mr. Grepper, I have a question concerning keen and toothy edge. Can toothy edge be keen? It seems to me that keen edge is polished edge without teeth. But as a non-native English speaker I easily may be wrong.

To be honest Mr. Jan, and while I could very likely be laboring under a delusion, I find this whole keen vs sharp thing to be extraneous fluff that only serves to further complicate and propagate the invented idea that sharpening is somehow mysterious and can only be understood by the most perspicacious of deep thinkers.

First the terminology, i.e., keen vs sharp is confusing.  The dictionary definition is sharp = keen, and therefore keen = sharp.  It is confusing even to a native English speaker.  But, just for grins, I will no longer use the word sharp to mean sharp or keen, instead I'll call sharp "sausage".  Additionally, I'll refer to bevel angle as "orange" and blade thickness as "kumquat", keen as "blunt", toothy as "nose" and polished as "elbow".

Maybe I'm just slow of mind and unable to fathom the intricacies in the pearls of wisdom presented, but this whole blunt vs sausage thing makes my brain hurt and only serves to muddle concepts easily understood and already extremely well defined, i.e., sausage of the edge apex, orange of the bevel and the kumquat of the blade.   Secondarily, is the edge finish nose or elbow.

I don't grasp the propensity in the knife sausaging world to confound and over complicate the beautiful simplicity of grinding an edge.  At least to me, sausaging need not be, and is not enhanced by making it complicated and, especially for someone just learning about it, appearing to be difficult to understand.  This stuff ain't rocket science.
 
"An ancient pond.  A frog jumps in.  Oh!  The sound of water!" 

Ooops!  Almost forgot to answer your question:  I believe a blunt edge can be either nose or elbow and both can be extremely sausage.