I know LLMs are terrible at playing chess because they just hallucinate moves(illegal ones). GothamChess made a lot of videos making fun of it. So in my AI agent project, I added a small chess engine and force the agent to only play moves output by the engine. And it was surprisingly good at it and we can now play real chess with LLMs. Check the project here if you are interested https://github.com/valmishq/valmis