Improved tree-based strategies for a Connect6 threat-based hardware design

Connect6 is a member of the k-in-a-row games family and attracts attention through its fairness and game complexity. Several very good strategies for Connect6 exist. In this paper we improve an already existing threat-based hardware design, which only evaluates the actual allocation of the game board. This strategy calculates a best move and waits until it wins or loses in the next two moves after the actual state. Our new proposed strategies think ahead and try to advance the player into a better position for the subsequent moves. We implemented three strategies with different winning chances, but all with clear advantages against the original strategy. This could be achieved without a much longer time for calculation and without the need of much more memory capacity. The implementations are validated on an Altera DE2 board, which contains a Cyclone II field-programmable gate array.