Connect Four Strategy: Rules, the Centre Column and Winning Threats
Connect Four is a two-player game of dropping coloured discs into a stand of seven columns and six rows. It looks like tic tac toe on a bigger board, but gravity changes everything: you can only play on top of what is already there. Here are the rules, what computers have shown about the game, and the strategy ideas that win most casual games.
Rules
- One player takes red discs, the other yellow. Decide who goes first with a coin flip.
- Players take turns dropping one disc into any column that is not full. The disc falls to the lowest empty space.
- The first player to get four of their discs in a row, across, down or diagonally, wins.
- If all 42 spaces fill up with no four in a row, the game is a draw.
Why the Centre Matters
There are 69 possible lines of four on the board. We counted how many of them use at least one space in each column:
| Column | Lines |
|---|---|
| Centre (4) | 51 |
| 3 or 5 | 39 |
| 2 or 6 | 27 |
| 1 or 7 | 15 |
The centre column is part of more than three times as many lines as an edge column, and the two middle spaces of the centre column each sit on 13 lines, against just 3 for a corner. That is why strong players fight for the middle and treat the outside columns as a last resort.
What Computers Found
Connect Four was solved by computer in 1988, independently by James Dow Allen and Victor Allis: with perfect play, the first player can always win. Later computer analysis showed that the result depends on the first disc:
| First disc | Perfect play |
|---|---|
| Centre | 1st wins |
| Next to centre | Draw |
| Any other | 2nd wins |
No human can play perfectly over 42 moves, so this does not spoil the game, but it does show how much the first move matters. Swap who starts each game to keep it fair.
When we let a computer play 100,000 games with both sides choosing columns at random, the first player won about 56%, the second about 44%, and fewer than 1 game in 400 was a draw.
Strategy Tips
- Take the centre: open in the middle column and keep adding discs there when it is safe.
- Look before you drop: before every move, check whether your opponent has three in a row with an open end, and block it.
- Do not give a gift: never play directly under a square your opponent needs; your disc gives them the step to reach it.
- Build two threats: aim for a position where you can win in two different places; your opponent can block only one.
- Odd and even rows: as a rule of thumb from Allis’s analysis, threats on odd rows (counting from the bottom) tend to help the first player, and threats on even rows help the second.
Variations
- Pop Out: on your turn you may remove one of your discs from the bottom row instead of dropping one.
- Five in a row: on a wider board, play for five instead of four.
- Paper version: draw a 7 by 6 grid and fill squares from the bottom up with X and O.
If you enjoy games that computers have solved, read our tic tac toe strategy guide, or try dots and boxes and Battleship.
For a much older two-player game with counting at its heart, see our Mancala rules guide.
FAQ
How do you play Connect Four?
Players take turns dropping discs into a 7 by 6 grid. Each disc falls to the lowest free space, and the first player to make four in a row across, down or diagonally wins.
Can the first player always win Connect Four?
Yes, with perfect play. The game was solved in 1988: the first player wins by starting in the centre column and playing perfectly afterwards.
What is the best first move in Connect Four?
The centre column. It is part of 51 of the 69 possible lines of four, more than any other column.
How many ways are there to win in Connect Four?
There are 69 possible lines of four: 24 across, 21 down and 24 diagonal.
How do you stop someone winning at Connect Four?
Check every move for three in a row with an open space, block it, and avoid placing a disc directly below a square your opponent needs.