Connect Four on 6 high, 7 wide grid, there are 4,531,985,219,092 positions for all game boards populated with 0 to 42 pieces. The game was first solved by James Dow Allen (October 1, 1988), and independently by Victor Allis (October 16, 1988). Allis describes a knowledge-based approach, with nine strategies, as a solution for Connect Four. Allen also describes winning strategies in his analysis of the game. At the time of the initial solutions for Connect Four, brute-force analysis was not deemed feasible given the game's complexity and the computer technology available at the time. Connect Four has since been solved with
Ploy (board game) the 3M bookshelf game series. The game is said to have a "chess-like feel". The game set includes a board and fifty pieces of various colors and shapes. The game is marketed as a "space-age strategy game". It is also considered to be one of the “better” chess variations. The game is long out of production. The following game mechanics are identical for all variations of play. The game board is square with nine spaces on a side. Vertical, horizontal, and diagonal lines connect the spaces. Players move their pieces along the lines. Each piece has a set number of