Yes, but an LLM will just call stockfish if it needs to play chess … sure if you arbitrarily constrain an LLM to use no tools it’ll suck at chess. But no one is using LLMs in isolation. Even consumer-grade, bone-stock ChatGPT has tools.

ChatGPT does not have stockfish as a tool it can call.

Yeah but it can just install it. It writes arbitrary code. It can do whatever you want it to do.