I think that the main problem here lies in meaning of "understand chess". You can say that computers understand chess because they are able to consistently bea

I think that the main problem here lies in meaning of "understand chess". You can say that computers understand chess because they are able to consistently beat best human players. Or you could say that they understand it because they are able to play it at all. Or you can say that they do not understand chess, because they use some combination of hard coded heuristics (and the evaluation function is nothing but that) and brute force, which is at first glance too trivial approach to be called understanding.