You make a move in Go, it feels good, you mentally play out likely lines of play and they feel good too, but there is a grey cloud obscuring some lines of play.

You make a move in Go, it feels good, you mentally play out likely lines of play and they feel good too, but there is a grey cloud obscuring some lines of play. You can't quite see every possible outcome, not even close. Uncertainty lies ahead in that cloud beyond our mental abilities. What do we call that uncertainty? It's quite similar to randomness whatever it is.