The problem with expertise
Chess is a complex game.
You start with two identical, perfectly mirrored sides, but once each player has made their first move, there are 400 possible board setups.
Make another move each, and you're now in one of 197,742 possible games. After three moves each, you're playing one of 121 million.
Players push each other into an increasingly divergent trajectory with each move, and each game grows into a sequence that has likely never been played before.
But as far as learning environments go, chess is incredibly kind.