# Can humans play Connect 4 perfectly?

Is it possible for a human to play Connect 4 perfectly? Have there been such players?

I am actually a Connect 4 enthusiast, but find it increasingly hard to memorize so many initial positions. Is it possible for a human to memorize some basic rules and tricks, as well as starting positions, and win atleast 80% of the games (starting 1st) against a perfect player?

Are there any simple rules that I've happened to miss, or any shortcut to memorizing the starting moves?

Connect 4 has been solved by Victor Allis in 1988. It is a first player win provided that the first disk is played to the middle column.

That paper I linked above has some heavy-duty analysis of board positions and expert play. I suppose it would be possible to memorize them, but I couldn't say whether you'd reach the 80% goal.

• I have seen that paper and found some of the rules too complicated. Commented May 23, 2015 at 6:32

As @ghoppe wrote, if you follow Victor Allis strategy you will win 100% of the games as white. While Allis Masters Thesis is indeed complicated, I easily implemented some of the insights, and I am just a recreational player.

1. Odd and Even Threats: because there are even number of locations (6) in each column, the first player (white) should create threats on the odd rows (3,5) and the second player (black) should create threats on even rows (2,4,6).

2. Zugzwang: is a situation wherein one player is put at a disadvantage because of their obligation to make a move. White can control the Zugzwang by creating a threat in an odd row.

3. Nomenclature: In order to better memorize positions and moves, there is a common language: The 7 columns are labeled ’a’ through ’g’, while the rows are numbered 1 through 6. For example the lowest square in the middle column is called `d1`.

4. The starting moves: white first move must be `d1`. In fact in perfect play, all five first moves are to the `d` column. If White starts with `c1` or `e1` she can still force a draw, but any of `a1, b1, f1, g1` first moves are a win for black. Black's 3rd move that is hardest to win is `b1\f1`, in perfect play White will win at the 41th move.

• The link to Allis' masters thesis is failing for me. Does it still work for you? Commented Jun 19, 2023 at 12:50
• yes, it is still works for me. try to google: A Knowledge-based Approach of Connect-Four or this link: citeseerx.ist.psu.edu/… Commented Jun 19, 2023 at 18:32
• Thank you. The second worked great. Commented Jun 19, 2023 at 23:57