Connect Four

1 Overview

Connect Four is a two-player strategy game published by Milton Bradley (now Hasbro) in 1974. Players take turns dropping colored discs into a 7-column, 6-row vertical grid. The first player to form a horizontal, vertical, or diagonal line of four of their own discs wins. If the grid fills without a winner, the game is a draw.

Connect Four looks simple but has surprisingly deep strategy. Mathematically, it is a solved game -- the first player can always win with perfect play -- but at the casual and intermediate level it produces tense, tactical battles.

2 Setup

1. Place the grid frame on a flat surface with the legs supporting it upright.
2. One player takes all red discs; the other takes all yellow discs (21 each).
3. Decide who goes first. The standard rules give no first-player advantage guidance -- flip a coin or let the younger player go first.

3 Gameplay

On your turn, drop one of your discs into any of the 7 columns. The disc falls to the lowest available row in that column. You cannot place a disc in a full column (all 6 rows occupied).

Players alternate turns. There is no passing or skipping. The game continues until someone wins or the board fills (a draw).

4 Winning

Win by connecting four of your discs in a line:

• Horizontal: Four across in the same row
• Vertical: Four straight up in the same column
• Diagonal: Four in a diagonal line (either direction)

The game ends the moment a four-in-a-row is formed. If both players claim a win on the last move, the player who just played wins (you can't win on your opponent's turn).

Draw: If all 42 spaces fill without a winner, the game is a draw. Draws are rare in casual play but common at high skill levels.

5 Strategy Guide

Control the Center

The center column (column 4 of 7) is the most valuable position on the board. A disc there can contribute to horizontal, vertical, and both diagonal lines simultaneously. Start by dropping into the center column. The player who controls the center has more winning threats.

Build Threats, Not Just Lines

A "threat" is a position where you need only one more disc to win. The goal isn't just to build your own line -- it's to create multiple simultaneous threats so your opponent cannot block all of them. Two threats at once is usually unblockable.

The Odd-Even Rule

This is the most important advanced concept: winning threats in even rows (2, 4, 6) tend to favor the second player; threats in odd rows (1, 3, 5) favor the first player. Controlling where your threats land on even vs. odd rows determines who gets to execute them. This is difficult to master but explains why top players seem to "waste" moves that don't look like progress.

Watch Diagonals

Beginners focus on horizontal and vertical threats and miss diagonal connections until it is too late. Always scan both diagonal directions before each move.

Don't Fill Columns Prematurely

Filling a column can cut off your own future plays. Leave columns with winning potential open as long as possible. A full column is a dead column.

6 The Math Behind Connect Four

Connect Four is a solved game -- the first player wins with perfect play on a standard 7x6 board, as proven by mathematicians Victor Allis and James D. Allen in 1988.

The total number of possible games is approximately 4.5 trillion. Despite this, a computer playing perfectly will win every time as the first player. The practical implication for casual players: going first is a genuine advantage, even if only a skilled player can fully exploit it.

On a 6x5 board (non-standard), the second player wins with perfect play -- a fun variant to try once you've mastered the standard game.

7 Variants

Five in a Row

Play on a larger grid or use the standard grid but require 5 connected discs to win. Much harder to solve and extends game length significantly.

Pop Out

Each turn, instead of dropping a disc in, you can "pop out" one of your own discs from the bottom of any column. All discs above it fall down one row. Adds enormous complexity and removes the "solved" nature of the standard game.

Pop Ten

Pop Out variant where popping out a disc also removes all discs of your color in that column. Creates a drastically different game.

8 FAQ