Shoulder hit
The play is a shoulder hit with respect to . It is a sly move with the main purpose of reduction, i.e. decreasing the potential territory of the opponent. And the main advantage of the move is that it is not easy to catch or cut off this stone.
Black can choose between playing at a or b. Each choice has its advantages and should be considered depending on where the shoulder hit happened. White wil usually respond by extending or jumping one point in the same direction, i.e. answering a at one of the points marked c or b at d. A short pushing battle may ensue.
See also: