A chess board is a closed system with fixed rules, as far as I know you only need a lot of computing power to apply the min-max algorithm to solve any chess game.
In a chess game there are no probalities, AI is about to independently recognizing patterns in noise and develop assumptions out of it. The trick human brains are applying here is called intuition.
That wasn't what people said in 1960 - as soon as AIs solve a particular problem we redefine intelligence to mean something different. Modern AIs (e.g. hypothesis generation toolkits) can be better at recognizing patterns in noise than humans. I bet in 20 years' time we'll see that - and we'll be having this same conversation about how pattern recognition isn't really intelligence.
In a chess game there are no probalities, AI is about to independently recognizing patterns in noise and develop assumptions out of it. The trick human brains are applying here is called intuition.