The problem I see with this prompting is he is going to great lengths instructing the LLM that he is a grandmaster and makes great moves etc. but nowhere in the prompt does he instruct the LLM to attempt to win the game of chess.

It may just be coming up with "good moves" that a "grandmaster" would make, but after all, grandmasters still lose 49% of their games, all the while making "good moves"

I would suppose that the LLM is actually wholly uninterested in victory given this prompting.