Cutting stones
A group of stones that divides the enemy forces into two or more groups. May initially consist of a single stone at a cutting point.
Here the stone is a cutting stone.
Black shouldn't sacrifice it, because if it lives the white group above it will be weak, and the white group on the side a little weak.
here is a good way to save the cutting stone from capture.
If the game goes this way breaks the possible ladder (White
at
).
The result is clearly advantageous to Black. The two stones have become very weak and it would be very troublesome to save them. But they are themselves cutting stones: if Black captures them, the initial cutting stone connects to the corner.
Therefore White should take better care of the upper stones.
This development is fine for Black, though.
In general, cutting stones shouldn't be sacrificed if they keep separated groups of the opponent which are even a little weak (they are key stones).
If however stones are non-cutting, like these two stones, saving them may have no strategic meaning and can be pointless.