I feel I went a little a little overboard with the vert count in the head section.
What would be considered a good count variation to keep a consistent low poly set pieces? ~5% / ~10% ~20% of vert/faces/tris?
lesson - Vert: 250 | Faces: 248 | Tris: 494
exercise - Vert: 280 | Faces: 278 | Tris: 556
It might be too many vertices for a low poly knight by overall all you did a fantastic job!
There is no rule to say it’s low poly. Sure it looks like low poly.
Because it’s all about getting the shape with a minimal amount of vertices.
If this is the shape you need to get a good knight shape object.
Hurray, you’ve done it, using low poly.
You can optimize, for example, the head could lose some vertices. But then you create a face with more than four vertices (N-gons). And lose the option to easily create edge loops, for more detail if needed.
The reason for low poly, it to have a study object to manipulate vertices. Not that many to make it difficult for the mirror proces of creating a knight.
Try to search on this forum, many others have asked this question.
Low poly is only an object if you have a purpose for it. I would not get too bogged down in the supposed need for it.
I agree
@Kevin-Brandon thank you 
@FedPete I get what you mean. It’s somewhere between visuals and poly count. Not an hard science.
@NP5 I understand that. My goal here is to create a chess set that is consistent, so, in this case, low poly is the way to go. I was just curious if there was some underlying principles that would define low poly. A bit like pixel art vs vector drawing vs digital painting.
On to the next lesson
Cheers!
You’re welcome! 
