Played on The Game of Y board
From website
Start: 6 stones for each player of their own color, arranged on the perimeter of the board as shown at left.
Play: Players take turns moving any one of their stones any distance along an unobstructed line, in any direction. Movement through a pentagon may follow either of the two forks that exit on the other side.
Goal: To be the first player to form a line of six adjacent stones. The line need not be straight as long as no stone has more than two neighbors.