Common Connect 4 mistakes

Connect 4 is simple, but the same errors come up again and again. See our Connect Four rules page for the full ruleset.

Rules mistakes

• Trying to place a disc mid-column. Every disc falls to the lowest empty space.
• Forgetting diagonals. Both rising and falling diagonals count.
• Counting a gap. The four discs must be unbroken. Three discs plus an empty space is not a win.
• Playing after the win. The game ends as soon as four in a row appears.
• Two discs in one turn. Players alternate single drops.
• Leaving the release open. Lock the bottom bar before you start, or discs fall out.

Playing mistakes

• Ignoring an opponent’s three in a row. Check every line each turn, not only the one you are building.
• Playing under the opponent’s threat. If your disc raises the space above it into a playable spot, the opponent takes their win.
• Playing only on the edges. The outer columns are part of fewer possible fours.
• Building only one threat. A single threat is easy to block. Aim for two.
• Blocking one move too late. A three that has two open ends may already be a win for your opponent.
• Treating a full board as a loss. A completely filled grid with no four is a draw.

Quick turn check

1. Can I win now?
2. Can my opponent win on the next drop?
3. If I play here, what does the space above become?
4. Am I building toward two threats?