Yon-ren-sei fuseki
A four-star opening formation that builds influence along one side of the board.
Also known as
Yon-ren-sei fuseki is an opening formation in which one player places four same-color stones on the four hoshi points running along one side of the board. The stones form a continuous row on either the upper or lower side, emphasizing influence and rapid development rather than immediate enclosure of a corner.
This pattern develops broad influence along that side and offers strong potential for large-scale fighting and moyo building. It is the four-stone extension of the ni-ren-sei and san-ren-sei formations: unlike those patterns, it uses four star-point stones along the side. Because several moves are committed to one area, its effectiveness depends on the opponent’s response and on maintaining a good balance of development elsewhere. It is also known as Four-star fuseki.