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
Connect 4x4 two sides. This can potentially take multiple slots of a single column on one side of the board out of play for all players even though they remain unoccupied by game pieces. The game is won by the first player who lines up four of his or her checkers in any direction: horizontally, vertically, or diagonally. Checkers can weave back and forth between the two grids as well which increases the number of ways to place four in a row. Connect 4x4 Connect 4x4 (spoken as Connect Four by Four) is a three-dimensional-thinking strategy game first released in 2009 by