The constraint is enforced at every move. Stockfish can never actually play against it. The only limitation is that its internal search tree imagines unconstrained future moves, which makes its evaluation slightly off and the engine effectively weaker. For the use case (handicapping for fun) that's an acceptable tradeoff
> The only limitation is that its internal search tree imagines unconstrained future moves.
Yes this is what I'm saying. Evaluation can be way more than just "slightly off" though and can make the evaluation MUCH weaker because it might go down "ply-routes" that aren't just suboptimal - they simply wouldn't work at all.
For example thinking it had a "move set" that lead to a checkmate but the final ply involves a bishop that is five squares away per my rule constraint mentioned earlier.
It's fine for fun but the statement that "Stockfish's skill level applies correctly" is not a true one at any moderate level of play. (above 1200 ELO).
That's why I suggested looking into Fairy which supports runtime rule variations.
Fairy would help with search tree accuracy but it's not expressive enough to cover everything, you can't encode "no captures for 5 moves" in an INI config. I'd still need the JS filtering layer for dynamic constraints, so you would end up in the same place with those cases.
Ah yeah that'll get complicated quickly. :( It'd be nice if stockfish or its variants exposed the "ply searcher" with some kind of a callback so you could quickly kill a ply based on your custom constraints.
When I was doing some research into rolling my own chess engine about 5 years ago I stumbled across this:
I was playing around with the idea of difficulty ramping, the first celeb would be more famous than the 2nd and so on.
I also want to go back through each celeb and add in what single thing they are most well known for, so for Edward Teller for example, i'd put "the father of the hydrogen bomb".
Where are you getting the stats from? I wanted to build something related but more real time (I don't have an iphone to check out the app but i'm assuming you don't have real time box scores). http://www.nba.com/news/termsofuse.html#priv9 (6)
https://constrainedchess.vercel.app/?fen=2b1kb2%2F8%2F8%2F8%...