Incidentally, there are a great many variant versions of chess with different piece-move rules (collectively sometimes called “fairy chess”), and I think even quite a lot of collected games for some of the more popular rule variants. Training an AI to play many types of fairy chess, and even arbitrary new just-invented ones, might be an interesting project that covers some aspects of generalizing out-of-distribution and positive transfer. A suitably-edited-for-the-variant version of Stockfish makes a pretty strong baseline for this. Using AlphaZero per variant is another obvious baseline.
Incidentally, there are a great many variant versions of chess with different piece-move rules (collectively sometimes called “fairy chess”), and I think even quite a lot of collected games for some of the more popular rule variants. Training an AI to play many types of fairy chess, and even arbitrary new just-invented ones, might be an interesting project that covers some aspects of generalizing out-of-distribution and positive transfer. A suitably-edited-for-the-variant version of Stockfish makes a pretty strong baseline for this. Using AlphaZero per variant is another obvious baseline.