> I paused reading to solve your first fictional example and ended up using the exact strategy that you explain in the next few paragraphs.
I did too, and really feel like it's the most natural strategy, even for regular chess players. I'm interested if OP has any anecdotal evidence that chess players would try to solve it by a "forward" algorithm rather than "backward." Even a natural chess player would get that this is a puzzle.
> anecdotal evidence that chess players would try to solve it by a "forward" algorithm rather than "backward"
I think the main point is less about the forward vs backward part, and more so about the assumed relative values of every piece, position, or configuration on the board. Anecdotally, playtesting did show that regular chess players tend to lean on preexisting heuristics that serve them really well in chess, but less so in echo chess.
Not sure how this data compares to other variants like Sovereign Chess. I bet there is a similar adjustment period required to unlearn some habits and learn new ones. Caveat to all this: after re-adjusting to the mechanics of a puzzle game and the specific implications entailed, I'm sure veteran strategy players would still outperform, on average. Even across broader genres like chess vs TBS vs 4X vs GS. There's likely some 'muscle memory' that the brain develops over time.
I did too, and really feel like it's the most natural strategy, even for regular chess players. I'm interested if OP has any anecdotal evidence that chess players would try to solve it by a "forward" algorithm rather than "backward." Even a natural chess player would get that this is a puzzle.