Connect Four

Connect Four is the 1974 Milton Bradley game (originally “Captain’s Mistress,” supposedly played by Captain Cook in his cabin during sea voyages) — a vertical gravity-based version of 4-in-a-row. Two players drop colored discs into a 7×6 grid; the first to get 4 in a row (horizontal, vertical, or diagonal) wins. In 1988, Connect Four was solved: the first player wins with perfect play, starting in the centre column.

How to play

• Setup: 7-column × 6-row vertical grid. Discs drop from the top and fill from the bottom up (gravity).
• Two players (Red and Yellow). Take turns dropping a disc into any column with empty space.
• The disc stops at the lowest empty cell in that column.
• First to get 4 of your discs in a row — horizontally, vertically, or diagonally — wins.
• If all 42 cells fill without a winner, it’s a draw.

The math: it’s solved

James Allen and Victor Allis independently solved Connect Four in 1988. Key result: the first player wins with perfect play, by starting in the centre column. From the centre opening, the first player has a forced win — though it requires deep look-ahead (20+ moves) to execute.

• First player (Red) wins with optimal play starting in centre column (column 4 of 7).
• Second player (Yellow) draws if Red plays sub-optimally.
• Yellow can force a draw, but cannot win against optimal play.
• Modern Connect Four engines (Mathieu Lecler’s solver) play instantly perfect from any position.

Beginner strategy

• Always start centre column. Column 4 (the middle) gives access to all diagonals from the bottom.
• Build multi-threats. A piece that creates 2 simultaneous threats forces opponent to block one, letting you win the other.
• Don’t stack vertically too early. 4 in a column is easy to block. Diagonal and horizontal threats are harder to defend.
• Watch the column heights. Each column fills from bottom. Knowing what’s in each column at each height is essential planning.
• Block opponent threats early. Once opponent has 3 in a row, you MUST block (or you lose).

Intermediate strategy

• The diagonal threat. Diagonals are harder to spot than rows/columns. Master detecting opponent diagonals 2-3 moves ahead.
• The “trap” setup. Place pieces so that the opponent’s forced block creates the foundation for your next threat.
• Don’t make the opponent’s 3-in-a-row. Avoid moves that “stack” beneath opponent threats.
• Centre control. The middle 3 columns (3, 4, 5) participate in most winning lines.
• Odd vs even-row threats. Threats on odd-numbered rows (counting from 1) favor the first player; even rows favor second. Set up threats on YOUR row parity.

Advanced strategy: parity

Connect Four’s deepest concept is “parity” — which row a winning threat exists in. Since the board fills from bottom up:

• Row 1 (bottom): first piece in each column. Odd parity (Red’s row, if Red plays first).
• Row 2: second piece. Even parity (Yellow).
• Row 3, 5: odd. Red’s rows.
• Row 4, 6: even. Yellow’s rows.
• Threats on YOUR rows are dangerous to opponent; threats on opponent’s rows can be filled in defensively.
• Endgame parity: if you have a threat on row 5 (yours) and Yellow has one on row 6 (theirs), Yellow can’t reach row 6 first because of gravity. You win.

Connect Four history

• 1974 — Milton Bradley releases Connect Four. Marketed by Howard Wexler and Ned Strongin as a single mechanical game.
• 1979 — TV commercials: Connect Four jingle (“Pretty sneaky, sis!”) becomes a cultural touchstone.
• 1988 — solved: Allen and Allis independently prove first-player wins. First widely-known commercially-popular game to be solved.
• 1992 — competitive scene: first organized Connect Four tournaments. World Connect Four Federation forms.
• 2010s — digital surge: Connect Four becomes available on every mobile and console platform.

Variants

• Connect Five. Needs 5 in a row instead of 4. Larger grid (usually 10×8).
• Pop Out. Players can also remove their own bottom piece from a column.
• 3D Connect Four. 4×4×4 grid. Many more winning lines.
• Connect Four Plus. Smaller 6×5 grid with diagonals of length 3 winning.
• Toot and Otto. Each player uses any color disc; must complete the word “TOOT” or “OTTO” with their colors.

Common mistakes

• Opening on a side column. Side columns can’t reach the centre with diagonals. First player gives up the win.
• Building under opponent’s threats. Placing pieces below opponent’s 3-in-a-row gives them the 4th.
• Missing diagonals. The 2 main diagonal directions plus 4 corners-to-corner lines are easy to miss.
• Stacking too high in one column. Tall single columns don’t create new threats; they just fill space.

FAQ

• Q: Can the first player always win? A: Yes, with perfect play. The center-column opening leads to a forced win.
• Q: How many cells in Connect Four? A: 42 — a 7×6 grid.
• Q: What’s the maximum game length? A: 42 moves if both players fill the board without winning.
• Q: Is Connect Four like Tic-Tac-Toe? A: Similar concept (n-in-a-row) but: bigger board, gravity, longer winning line. Much deeper game.

For other n-in-a-row games, try Tic-Tac-Toe, Gomoku, Ultimate Tic-Tac-Toe, or Hex.