Connect Four

Connect Four was invented by Howard Wexler in 1973. He wanted to create a game that had a vertical game board in contrast to the typical tabletop board style. As he wasn't a mathematician, he worried a lot about the game falling into stalemate often, but that turned out to not be the case. You can read an interview of him by Fordham News here:

https://news.fordham.edu/fordham-magazine/toy-story-catching-up-with-howard-wexler-inventor-of-the-classic-game-connect-4/ (opens new window)

This paper dives into many human strategies that can be carried out in your next game of Connect Four. Our project is more focused on algorithm-developed game strategies, but you might find these fascinating!

http://www.informatik.uni-trier.de/~fernau/DSL0607/Masterthesis-Viergewinnt.pdf (opens new window)

This Numberphile video touches on the many possibilities in a game of Connect Four and explores how the first player can always win if they play perfectly.

Connect four is a zero sum game where the terminal game state can be a single player winning, a single player losing, or a draw. For instance, given an initial board:

win states for connect 4

There are a few ways for one player to win, and also several ways for the other player to optimally win in the very next move.