Contact Capture
Contact capture rules define how pieces are captured through direct contact. Here are the basic types of capture.
In the diagram, using (1), stone (A) cannot be captured because it is still in contact with stone (B), and stone (B) cannot be captured because it is in contact with (A). Using stone (2), stone (B) cannot be captured because it is in contact with stone (C).
If it were the other player's turn, stone (B) could not capture either stone (1) or (2). Stone (A) can capture stone (1) because it is not in contact with any other stone. Stone (C) can capture stone (2).
In the simple way, stone (B) removes stones (1) and (2). Stone (C) removes stones (2) and (3), while stone (C) also removes stones (3) and (4).
Stone (1) is threatened by stones (A) and (B). Stone (2) cannot be removed because it is threatened by stones (B) and (C). Only stones (3) and (4) can be removed, and that is by stone (C).
Stone (C) can remove stones (2) and (4), and stone (C) can also remove stones (3) and (4). Stone (B) cannot remove stones (1) and (2) because they are in contact with each other.
In this way, stones (2), (3), and (4) will remove stone (C).
Stone (2) could be removed by stones (B), (C), and (D). Therefore, in this picture, no stone can be removed. If stone (D) were a blue stone, then it would be possible to remove stone (C).
In this way, stones (1), (2), (5), and (6) can remove the opponent's stone (B).