One of my two favorite go proverbs is this:
If your opponent has all four corners, you should resign.
On the go board, it is easiest to cover territory in the corners. If you have given all four corners to your opponent, you are probably losing. The advice is clear, concrete and to the point.
My other favorite is this:
If you have all four corners, you should resign.
Again: clear, concrete, to the point. And seemingly the exact opposite of the first proverb. How can they both apply?
Suppose you play against a better player. When you take the corners, your opponent takes something else, otherwise she wouldn’t give the corners to you. Even if you are leading in territory now, she will use the influence she gained elsewhere to surpass you.
The same deed has a different result when the doer is a master. The master knows why.