First of all, I am explicitly not asking for a list of endgame principles, nor am I asking for resources to study endgames from.
My question is: How does one develop endgame theory? The main motivation of my question is that I have been trying to study endgame theory for a chess variant (atomic chess, as it were) and there is precious little of it. I am quite literally writing new theory the deeper I study.
I'm looking for answers that could address either or both of the following points, in regular chess or in chess variants:
- How endgames (regular chess or any chess variant) were analysed, organised and codified over the decades until we have our present-day knowledge;
- How to study endgames, but without access to any books or professional games (just a chess set, a brain, an engine, tablebases, and lots of patience.)