Is Connect 4 a Solved Game? (What Does That Even Mean?)

A vintage Connect Four game by Milton Bradley
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For a long time, I would play Connect 4 with my favorite uncle and wonder how he always managed to win. It did not matter how I tweaked my strategy or how clever I thought I was; I just could not win if I played with him. What was his secret? Had he “solved” Connect 4?

Is Connect 4 a solved game? Yes, Connect 4 is a solved game. That means that there is a specific strategy that a player can use to win a round of Connect 4 each and every time. However, the player has to play a ‘perfect game’ in order to win using that particular strategy. Those who know the solution to Connect 4 have the upper hand in a game. 

So, my uncle’s secret was that Connect 4 is a solved game, and he knew the solution. I am tempted to shriek at him and call him a cheater, but the reality is that since finding out for myself, I have used this knowledge to my advantage too. 

Want to become the ultimate champion at Connect 4 in your household too? All you need to do is read on. Below we take a closer look at when Connect 4 was solved, what that really means, and how you can use the solution to win future games of Connect 4 too. 

Connect 4 – Limited or Unlimited Possibilities of Play?

When playing a game of Connect 4 for the first time, you will be astounded at just how many possible moves there are. When I first started, I must admit that I played at random. I was not yet aware of the strategy involved in playing the game, and I often got my ass kicked as a result. 

The reality is that there are not just “many” possible moves in Connect 4 – there are more than 4 trillion ways to fill a standard Connect 4 rack! The complexity of the game is measured by the number of possible rack positions. According to Numberphile, on a standard 6 high by 7 wide Connect 4 rack with 0 to 42 game pieces (or discs), there is a total of 4,531,985,219,092 possible positions. Imagine how much work must have gone into actually solving the game!

If you’re more of a visual learner, I suggest you take a look at the following video from the YouTube channel Numberphile

Video Source: YouTube / Numerphile 

Who First Solved Connect 4?

You might be wondering who the first person to solve Connect 4 was and how he/she did it. Before computers were used to play games, Connect 4 was actually not considered a “solved” game, but that all changed with the dawn of the digital age. 

The first person to solve Connect 4 was James Dow Allen (in 1988), and he used a computer to do it! At the time, computers were around, but algorithms were not quite as advanced as today, which means that “brute force” methods were not possible then. 

According to PC Magazine, “Brute force”, in computer science, refers to general computerized problem-solving techniques that use “the systematic, exhaustive testing of all possible methods” to solve a problem. Since 1988, computer technology and algorithms have come a long way, which means brute force has been used many times to Connect 4 and other puzzle games. 

Let us get to the good stuff…who actually solved Connect 4?

The game was officially solved by James on the 1st of October 1988. Of course, he found that the game can be won over and over if a player follows a perfect game strategy. That’s not always possible with humans! James went on to write a book on how to win at Connect 4, which is still available for purchase today. In his book, The Complete Book of Connect 4he includes the history of Connect 4, strategies of play, and a variety of puzzles.

Shortly (just 15 days after, in fact) after James Dow Allen solved Connect 4, another man, Victor Allis, independently solved Connect 4. Victor Allis has since published a knowledge-based approach to solving the game that features 9 strategies to ensure a win. And they work!

Outdoor 4 in a Row giant game set
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What is the Solution to Connect 4? | How to Win at Connect 4 Every Time

Now that you know that Connect 4 is a solved game, you probably want to know the solution so that you can get to work learning the strategy and subsequently winning every game you play hereafter. Nothing wrong with that – I did the exact same thing!

What James Dow Allen discovered was that a player can always win if he/she starts the game first and plays the middle column. This opens up more opportunities for player 1 to get 4 discs in a row, in any direction. He also found that if a player chooses another column to play first, player 2 can force a draw every time.

So, what is the strategy to winning at Connect 4? Well, as the solution suggests, you need to make sure that you control the center column, but that is not the only way to win. Just because there is a fail-proof way of winning Connect 4, it does not mean that there are no other ways to win the game. What if you start second? What if you do not know about the actual solution to the game? Well, that is when you need to incorporate a few clever strategies to win. 

Below are a few ways that you can increase your chances of solving/winning Connect 4 every time you play. 

1. Controlling the center.

Okay, we have mentioned this already, but it is worth a second mention. Controlling the center is the best way of winning. The Connect 4 rack has an odd number of columns, which means that if you play your discs into the middle column, you have more chance of making connections in every direction. 

How-to: simply slot your first disc into the bottom center slot.

girl plays Connect Four
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2. Paying attention to and blocking your opponent.

You might not be able to win the game, but you can certainly deter your opponent from winning, which is just as good. Defend against your opponent’s tactics as much as possible.

How-to: you can do this by focusing on placing your discs in the way of each move of your opponent instead of actually forming your own 4 in a row. 

3. Playing offensively.

Playing defensively and blocking your opponent’s moves is one strategy that works, but that does not mean that playing offensively does not have merit. In fact, it is a great strategy to employ to improve your chances of winning. 

How-to: build rows outwards horizontally or use discs to create diagonal connections with your rows and columns.

4. Planning a few moves ahead.

Thinking ahead is always a good thing, in all areas of life. Just like in all strategy games, players need to think ahead, but in Connect 4, you can plan ahead to distract your opponent from your actual intended move. 

How-to: if you are aiming for a specific win, place your discs on the rack in more than one position where you can start forming a row. This will get your opponent’s attention and hopefully send them off to blocking your moves, leaving your true intended winning move free and available for you to play. 

boy playing four in a row
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5. Setting a number 7 trap.

A “7 trap” is a popular strategy for those who have been playing Connect 4 for years. This strategy involves placing your discs into the shape of a 7 on the rack. You can create the 7 configuration in any direction o way, including upside down, backward, or even upside down and backward! Why do this? The 7 trap allows you to make 4-in-a-row connections in multiple directions. 

Last Word

If you have your heart set on winning Connect 4, knowing the solution to the game can be quite helpful. I have certainly found a lot of value in it. At our last family gathering, I surprised my uncle with a few winning moves of my own – and I won. By considering the abovementioned strategies of winning Connect 4, you can greatly increase your chances of being the next Connect 4 champion in your household and social circle.