Dark to move after 22 discs, with 1 column already full.
Connect four within 4 of your own moves. Exactly one column starts the win; any other lets the opponent off.
What the position is about
- forcing sequence — The solution is a series of threats, each one leaving the defence a single answer.
- diagonal four — The winning line runs on a diagonal, the hardest kind to see.
Finding the way in
In four-move wins, track which spaces become playable after each forced block; the final double threat often appears two rows above where you start.
Play the position in your head from the opponent's side: what would you do against your favourite move? If there is a good answer, try the next candidate.
Show the first move
Start with e4. Played out against the stiffest resistance, the whole line goes: e4 e5 b6 e6 c3 c4 c5.
Solve it and the next puzzle of the same game is one tap away. Your solved puzzles are ticked in the list, in this browser only.