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
CT Connect model and support the relevant CSTA protocol standards. Several telecommunications equipment vendors have used CT Connect as a laboratory CSTA reference to test their own products' compliance with the standard. CTI servers like CT Connect must operate in a heterogeneous computing environment and must interoperate with other system components chosen by application developers and users. CT Connect takes an "open" stance towards other system components, interoperating with a wider range of components than other CTI servers. This open stance is undoubtedly one reason that CT Connect has survived for 20 years while other competitors such as IBM CallPath and Novell