Both can be true at the same time. A lot of the time the best move is obvious. However, if you play the top move 20% of the time, you will also play the top mov

Both can be true at the same time. A lot of the time the best move is obvious. However, if you play the top move 20% of the time, you will also play the top move in a lot of cases where it's not obvious. Given enough games, it's detectable.