In online chess the fact that all moves have to go through a server is a bit of an issue. First, players who are closer to the server get a lower latency, which is crucial under time pressure. Second, it’s a financial toll which is eventually charged on the players. Finally, it makes it harder to organize large tournaments, and overall to scale up the service.
Could online chess, or any online 1vs1 online board game for that matter, use NKN for decentralization? I think so.
I think the organization of a chess game can be divided in three parts : pairing, playing and adjudicating.
Pairing consists in matching game requests between players. I don’t think this part can or needs to be decentralized. As far as I can tell, it still needs a centralized server but this should not be too much of an issue since pairing is done only between games, not all the time.
Playing the game is what should be decentralized, IMHO. In a IRL tournament, the arbiter is not constantly watching over the board to make sure everything is proceeding correctly. Players self-regulate themselves. There is no reason it should be different online, thus moves need not to go through a central server to be validated. They can be communicated directly between the players.
Adjudication, and more generally arbitration such as anti-cheating measures, can be done through a central server which would collect signed score sheets (cryptography makes the equivalent of a signed score sheet obvious). Just as for pairing, I don’t think it would make sense to try to decentralize this part.
I think this could be a great use case for NKN, and a cool way to demonstrate the potential of the technology.