Connect 47×6 grid

Goal of the game

Line up four of your discs — horizontally, vertically or diagonally — before your opponent does.

Discs drop to the bottom of the chosen column: you choose the column, never the cell.

How it plays

• A grid of 7 columns by 6 rows, 42 cells, 21 discs per player.
• On your turn you drop a disc into a column: it takes the lowest free cell.
• The game ends as soon as a line of four appears, in any direction.
• A full grid with no line of four is a draw. Rare between careful players.

The centre column decides the game

• The centre column takes part in more possible lines than any other: seven, against only three for an edge column.
• The winning first move is always in the centre. The game is solved: the first player wins by starting in the middle and playing correctly afterwards.
• If your opponent takes the centre, occupy the two columns next to it: it is the best reply.
• Edge columns are usually only useful at the end of the game, or to force a move.

The double threat

• The real lever of the game is not lining up four, it is creating two threats at once. Your opponent can only block one.
• The classic shape: three discs in a line with a free cell on each side. They cannot close both.
• Another shape: two threats in two different directions crossing on the same cell.
• A single threat, however visible, never wins against an attentive opponent.

Parity, the idea that separates levels

• Each column fills from the bottom up: a cell only becomes reachable once the one below is taken.
• Count the rows: the first player naturally fills the odd rows (1, 3, 5), the second player the even rows (2, 4, 6).
• A threat placed on a row of your parity will come true on its own if the game goes all the way up that column.
• That is why an experienced player prepares high threats without ever playing them: they wait for the column to climb up to them.

The mistakes that cost the most

• Playing the edges early on. It gives up the centre for nothing.
• Blocking without building. Every defensive move should also prepare one of your threats.
• Handing over the cell above. Before playing, always check what your disc offers your opponent right on top of it.
• Filling a column by reflex to block a threat that was not active yet.

Controls

Keyboard and mouse

• Click a column to drop a disc; a preview shows where it will land.
• Keys 1 to 7 play the matching column directly.
• Full columns are greyed out.

Touch screen

• Tap anywhere in a column to play there.
• The winning line lights up at the end of the game.
• With two players, pass the device back and forth after each move.

Frequently asked questions

Does the first player always win?

Yes, in theory: Connect 4 has been solved since 1988, and the first player wins by starting in the centre column and playing perfectly afterwards. In practice, the slightest inaccuracy is enough to open the game up again.

What is the best first column?

The centre column, without hesitation. It takes part in seven possible lines, against three for an edge column.

Can you win diagonally?

Yes, in both directions. Diagonals are actually the lines most often missed, because the eye naturally follows rows and columns.

What is a double threat?

A position where you can win in two different ways on your next move. Since your opponent can only block one cell, the game is won.

What happens if the grid fills up?

It is a draw. That is rare: with 42 cells and four directions for a line, a game with no winner takes two very defensive players.

More classics, free as well

• Solitaire — classic Klondike, draw one or draw three
• Spider Solitaire — ten columns, sequences to build, three levels
• Sudoku — the 9×9 grid, four levels, pencil marks