THE FULL READ
Connect Four was mathematically solved in 1988 by James Allen, and independently by Victor Allis the same year. The conclusion: with perfect play from both sides, the first player always wins, and the winning strategy starts by dropping the opening disc in the centre column. Knowing this fact ruins the game for most adults. *Not* knowing it makes it one of the best gateway strategy games for kids.
The centre-column opening is the single biggest tip and the biggest spoiler. The centre column participates in the most possible four-in-a-row combinations (it intersects every horizontal, vertical, and both diagonals). Controlling it is roughly equivalent to controlling the centre in chess but more deterministic. New players who learn the centre-first rule beat opponents who don't, almost every time.
The double-threat (or "fork") is where Connect Four becomes briefly interesting between two intermediate players. Setting up a position where you can win in two different columns next turn — forcing your opponent to block only one — is the same tactical concept as the chess fork. Spotting and defending against forks is the actual skill ceiling of casual Connect Four, and it caps out around the level of an attentive 10-year-old.
The reason Connect Four still has value is that kids learn pattern recognition from it. A 7-year-old who can spot a horizontal three-in-a-row and block it has just internalised threat-evaluation, which transfers to Chess, Othello, and Gomoku. The game's pedagogical value is enormous; its competitive value is zero.
For adults wanting the Connect Four feel with actual depth, Gomoku (five in a row on a 15x15 board, no gravity) is the natural upgrade — same core idea, vastly more strategic richness, and not solved at the human level. Quoridor is the modern abstract that occupies a similar "teach in 60 seconds, play for years" niche.