Connect Four is a two-player game in which the players first choose a color and then take turns dropping colored discs from the top into a seven-column, six-row vertically-suspended grid. The pieces fall straight down, occupying the next available space within the column. The object of the game is to connect four of one's own discs of the same color next to each other vertically, horizontally, or diagonally before your opponent. There are many variations on the board size, the most commonly used being 7x6, followed by 87, 97 and 107. The game was first sold under the famous Connect Four trademark by Milton Bradley in February 1974. The game was solved mathematically by James D. Allen (October 1, 1988), and independently by Victor Allis (October 16, 1988). With perfect play, the first player can force a win by starting in the middle column.