Connect Four

Q: How do you play Connect Four?

Two players. 7-column × 6-row vertical grid. Players take turns dropping colored discs into any column. Disc falls to lowest empty row in that column (gravity). First to align 4 of own color in a row (horizontal, vertical, or diagonal) wins. If board fills without connection = draw. Simple rules learned in 2 minutes but deep strategy of anticipating multiple moves ahead + creating unavoidable double-threat positions.

Q: Can Connect Four be solved?

Yes — SOLVED game as of October 1988 by James D. Allen (USA) + Victor Allis (Netherlands) independently. With perfect play by both sides: FIRST PLAYER WINS if they open in the center column (column 4). Any other first move by first player = draw with best play. So opening move dictates outcome. Modern computers play perfectly; humans cannot compete with engines. Pascal Pons' open-source solver is standard benchmark.

Q: What's the best opening move?

For first player: Center column (column 4). This is the ONLY first move that leads to a forced win with perfect play. Any other opening (columns 1-3 or 5-7) leads to draw or loss with best defense. Second player after first player opens center: best response is also center column (stack on top). Center squares participate in most winning lines. Advanced play from there follows solved-game analysis.

Q: How is Connect Four different from Tic-Tac-Toe?

Both are align-N games but Connect Four is dramatically deeper: (1) Larger board — 7×6 = 42 squares vs 3×3 = 9. (2) Need 4 in a row vs 3 in a row. (3) Gravity placement in Connect 4 (can't place anywhere) vs free placement in TTT. (4) Solved differently — Connect 4 first-player wins with perfect play; TTT always a draw with perfect play. (5) Games take longer (avg 15-25 moves vs 5-9). (6) Connect 4 has genuine strategic depth; TTT is trivial after age 8.

Q: Who invented Connect Four?

Commercial version: Milton Bradley 1974 (marketed as 'Connect Four'). But similar games predate the brand — 'Captain's Mistress' allegedly played by Captain James Cook on 18th-century voyages (unverified but popular story). Similar 'align-4' games in various cultures for centuries. Milton Bradley (now Hasbro) owns the trademark + physical game design. Digital solved-game analysis: James Allen + Victor Allis independently 1988.

Q: Is Connect Four a good game for kids?

Yes — excellent introduction to strategic thinking. Ages 6+ can play + enjoy. Simple rules (2-minute explanation), but strategic depth grows with skill: (1) 6-year-olds learn threat recognition, (2) 10-year-olds learn double threats, (3) teens can master forcing sequences + parity theory. Also great for spatial reasoning + planning ahead skills. Widely used in schools + educational settings. Commonly first 'real strategy' board game after simpler games like Tic-Tac-Toe + Snakes & Ladders.

Officially Connect Four (Hasbro/Milton Bradley)

Two-player vertical strategy game — players drop colored discs into a 7-column × 6-row grid, aiming to be first to connect four of their color in a row (horizontally, vertically, or diagonally).

📐vertical grid frame⏱~5 min🌤indoor

Photo · Wikipedia

What is Connect Four?

Connect Four is a two-player abstract strategy game published by Milton Bradley (now Hasbro) in 1974. The game predates the branded version — variants of 'four-in-a-row' games existed for centuries (called 'Captain's Mistress' allegedly played by Captain Cook on 18th-century voyages). Solved game (1988, James D. Allen + independently Victor Allis) — with perfect play, the first player wins by playing the middle column first. 7×6 grid: columns numbered 1-7 (or A-G), rows 1-6. Players take turns dropping colored discs (typically yellow vs red) into columns from top; disc falls to lowest empty row in that column (gravity-based placement, no free placement). Winner is first to align 4 consecutive discs of their color: horizontally, vertically, or diagonally. If board fills without connection = draw. Deceptively deep for its simple rules — probability + tactics dominate; elite play involves anticipating 15+ moves ahead. Standard as computer science AI teaching example (minimax, alpha-beta pruning). AI has fully solved game since 1988; humans cannot compete with modern engines. Popular in classrooms, homes, cafes, mobile apps worldwide. Estimated 100+ million copies of Hasbro version sold since 1974. Multiple variants: Connect 5, Connect 6, Gravitrips, Score Four (3D 4×4×4 grid). Competitive tournaments exist informally (Board Game Arena leaderboards); no official world championship.

Quick facts

How it works

Objective

Be first to connect 4 of your color discs in a row — horizontally, vertically, or diagonally.

Match structure

Alternate turns dropping discs into columns. Discs fall to lowest empty row in chosen column. Game ends when: (a) player connects 4 = win, or (b) board fills = draw.

Rules

Basic rules

7×6 grid, 42 slots
7 columns × 6 rows. Players start with 21 discs each.
Alternate turns
One disc per turn dropped into any column with space.
Gravity placement
Disc falls to lowest empty row in chosen column; cannot be placed freely.
Win = connect 4 in a row
Horizontal (row), vertical (column), or diagonal (both directions). First to connect 4 wins.
Full board = draw
If all 42 slots filled with no connection = draw (rare with even remotely competent play).
Cannot pass turn
Must make a move each turn; unlike some strategy games.
First player advantage
Solved game (1988) — with perfect play, first player wins if they start in center column.

Advanced rules

Solved game (Allis + Allen 1988)
First player wins with perfect play if opens in center column (column 4). Ties/losses only if first player makes mistake.
Threats + double-threats
Advanced play creates 'threats' (three-in-row with open ends) — opponent must block. Double-threats (2 simultaneous 3-in-rows) cannot be blocked = win.
Zugzwang (waiting move)
Sometimes best move is 'wasting' turn in irrelevant column to force opponent into bad spot.
Odd + even threats
Threat squares in odd rows (from bottom) favor first player; even rows favor second player — parity strategy.
Column control
Control of center column (column 4) is critical — it participates in most winning lines.
Endgame theory
With <10 pieces remaining, forced sequences often decide game — expert analysis crucial.
Variants: Connect 5, 6, Gravitrips
Connect 5 on larger board; Connect 6 (Taiwan, 2003) allows 2 stones per turn.

Scoring

Binary — win, lose, or draw. No points; tournament formats use best-of-3 or best-of-5.

Action	Points
Connect 4 of own color	WIN
Opponent connects 4	LOSS
Board fills without connection	DRAW (extremely rare with good play)

Win condition · First to align 4 discs of own color horizontally, vertically, or diagonally.

Playing area

Called

vertical grid frame

Dimensions

7 columns × 6 rows = 42 slots. Plastic frame 30×25cm typical; discs 3.5cm diameter.

Vertical plastic frame with 7 columns; each column has slot at top for dropping discs; discs stack from bottom up (gravity). Two-player alternating.

Equipment

Connect Four game
Hasbro plastic version ($10-15): vertical yellow frame, 21 red discs + 21 yellow discs (42 total).
Discs (42)
Plastic tokens, 3.5cm diameter — 21 per color.
Grid frame
Vertical plastic frame with 7 columns; slide lever at bottom to reset (drops all discs).
Paper + pencil version
Draw 7×6 grid; use X + O or two colors; free / DIY.
Digital versions
Countless mobile apps, browser games, Boardgamearena.com etc.

Officiating

Self-officiated. Physical game gravity enforces move legality automatically. Digital versions enforce rules programmatically.

Strategies

Play center column first (as first player)
Column 4 is critical — participates in most winning lines. Solved game confirms first player wins with center opening + perfect play.
Create + defend threats
'Threat' = three-in-row with open end forcing opponent block. Create your own; block opponent's immediately.
Look for double threats (forks)
Two simultaneous 3-in-rows in different directions — opponent can only block one, so you win next turn.
Odd + even strategy
Advanced concept: first player wants threats in odd rows (from bottom); second player wants even rows. Parity of rows matters in forced endgames.
Zugzwang (waste turns)
Sometimes best move is 'wasting' turn to force opponent into losing position (unable to make good move).
Don't stack unnecessarily
Placing discs above opponent's disc gives them free height for their diagonals.
Watch diagonals carefully
Diagonal wins often overlooked; both directions (NE-SW + NW-SE) count.

Terminology

Connect 4: Four consecutive discs of same color in a row (horizontal, vertical, or diagonal).
Threat: Three-in-row with open end — forces opponent to block or lose next turn.
Double threat / Fork: Two simultaneous threats — opponent can only block one, winning move follows.
Column / Col 1-7: Vertical stack of 6 slots; discs drop into columns.
Row 1-6: Horizontal level; row 1 is bottom.
Gravity: Discs fall to lowest empty slot in column — cannot place freely.
Diagonal: 4-in-row at 45° angle — two directions (NE-SW + NW-SE).
Blocked: Opponent's disc placed in a spot preventing your 4-in-row.
Open threat: 3-in-row where next disc completes 4-in-row.
Zugzwang: German chess term applied to Connect 4 — position where any move worsens position.
Odd/Even parity: Row number's parity — advanced strategy concept for who benefits from certain threat squares.
Draw: Board fills without either player connecting 4 (rare in serious play).
Perfect play: Optimal moves per solved-game analysis.

Major competitions

No formal world championship — casual game
n/a · worldwide
Online play (Boardgamearena.com, mobile apps)
ongoing · global online · since 2010
Computer/AI Connect Four championships
informal · academic AI community · since 1988

Where it is played

Governing bodies

Hasbro (owns Connect Four trademark)
Founded 1923 · Pawtucket, RI, USA
Official site ↗
No formal governing body for competitive play
n/a

Famous names & records

Famous athletes

No professional Connect Four players — casual game only
James D. Allen (USA) — first to solve Connect Four October 1988
Victor Allis (Netherlands) — independently solved Connect Four October 1988 (published PhD thesis)
Pascal Pons (Belgium) — created 'ultimate' open-source Connect Four solver used as benchmark

Records

Copies sold globally (Hasbro/Milton Bradley)
Hasbro — 100+ million since 1974 (2020)
Year game was solved
James D. Allen + Victor Allis (independently) — October 1988 (1988)
Perfect first-player win move
Solved by Allen + Allis — First player must open in center column (col 4) (1988)
Maximum game length
n/a — 42 moves (full board draw) — theoretical (2020)

Learn this sport

beginner

1
Learn basic goal + gravity rules
First game explains itself in 2 minutes. Focus on connecting 4 anywhere.
2
Play 20+ games with family/friends
Get comfortable seeing threats + blocks in all directions.
3
Play center columns
Discs in center columns participate in more winning lines than edge columns.

intermediate

1
Learn to create double threats (forks)
Set up positions where 2 simultaneous 3-in-rows exist — opponent can only block one.
2
Recognize diagonal patterns
Diagonal wins often missed; check both NE-SW + NW-SE constantly.
3
Study opening theory
First player wins with center opening + perfect play — but 99% of humans make small errors.

advanced

1
Learn odd + even parity theory
Advanced concept: which rows benefit which player in endgame threat calculations.
2
Play online at high level
Boardgamearena.com Connect Four leaderboards; mobile apps with rating systems.
3
Study computer analysis
Pascal Pons' open-source solver; Victor Allis' PhD thesis; John Tromp's C4 web pages.

Frequently asked

How do you play Connect Four?+