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

9 Common Mistakes

• Playing purely defensively: Blocking every opponent threat without simultaneously building your own winning threats puts you in a permanently reactive position. The best Connect Four players force their opponents to block them — not the other way around.
• Missing the double threat setup: The most powerful winning position in Connect Four is creating two simultaneous winning threats at once. Your opponent can only block one of them. If you are not actively building toward double-threat positions, you are missing the strategic core of the game.
• Abandoning the center: Column 4 (center) provides more diagonal, vertical, and horizontal winning possibilities than any other column. Giving up center control in the opening is a structural disadvantage that compounds as the board fills.
• Not checking diagonals: Beginners often focus on horizontal and vertical threats and overlook diagonal connections. Before every drop, verify that neither you nor your opponent has a diagonal threat building through the target column.
• Filling a column prematurely: Before placing a piece, check if that column is a component of an unfinished winning sequence — yours or your opponent's. Filling a column too early can permanently destroy a viable winning path.

10 Tournament & Competitive Play

Connect Four Is a Solved Game

Connect Four was mathematically solved in 1988 by James Dow Allen and independently by Victor Allis. With optimal play, the first player always wins by starting in the center column (column 4) and following a specific strategic tree. This is a proven mathematical result — the first player cannot lose against any defense with perfect play.

This knowledge does not ruin casual games because optimal play requires remembering and executing a very large decision tree in real time. Competitive play typically uses time controls (30–60 seconds per move) to prevent long calculation periods that would make the solved nature more accessible.

Competitive Format

Organized Connect Four competition uses best-of-5 or best-of-7 match formats. Players alternate who goes first each game to balance the first-player advantage across the match. Online platforms like BoardGameArena host rated Connect Four matches using ELO-style ranking systems, allowing players to track improvement over time.

Pop Out Variant for Competitive Play

Because the standard game is solved, experienced competitive players often prefer the "Pop Out" variant: instead of only dropping a piece, a player may alternatively pop a piece out of the bottom of any column they own, causing all pieces above it to fall down one space. This single rule change breaks the solved nature of the game entirely and creates a significantly richer strategic environment. Pop Out is the preferred format for players who have mastered standard Connect Four.