Connect four with App Designer

Connect-4, the classic strategy game for two players, has been entertaining and challenging players for decades. Whether playing on a physical board or a computer, the objective remains the same - to place four of your colored chips in a row, column, or diagonal. Over the years, researchers have explored various approaches and strategies to master this game, from brute-force techniques to sophisticated artificial intelligence algorithms like minimax and negamax. However, with advancements in technology and increasing game complexity, the brute-force approach is no longer a viable solution.

In 1974, Connect-4 was released in its modern-day form by Milton Bradley, previously known as "The Captain's Mistress." It has since been played with various rule variations, making it a popular subject for game theory and artificial intelligence research. In 1988, Victor Allis solved the game, demonstrating that with perfect play, the first player can always win if they choose the middle column first. If they choose another column, the second player can always ensure a draw. Join us as we delve into the fascinating world of Connect-4 and discover new strategies and techniques to become the ultimate champion!

Simple & effective winning tactics of Connect 4 a player should know

This game might seem simple, but it needs a lot of strategies and tactics to ensure a winning result; therefore, being aware of these strategies is essential. Let us quickly discuss common strategies before going on to how the game is designed. One of the basic strategies of this game is to place your disks somewhere in the middle since this opens up your win options in any direction. The computer's moves designed by this code use a basic win/block strategy which checks for 3 in a row, column or diagonal by either the player or the computer. Therefore, it would be reasonably straightforward to set up a winning strategy against the computer and simultaneously be aware that the computer has its basic strategy to prevent you from winning.

Another vital approach to use as a player is to plan a couple of different moves in advance to anticipate a reactionary move by the computer to block you in one direction. That will still leave you with other possible winning moves to set yourself up for a win.

 It's also vital to make moves that don't work in favour of the opponent(computer). The player must be looking for 3-connection moves that the computer could make and try to prevent them. Preventing 3-connections will also prevent the computer from setting up a trap such that a win can be achieved from multiple directions. The difference between winning and losing happens when you take advantage of the computer's mistakes.

Understanding the implications of your moves in advance would help you develop a strong defensive and offensive game plan. A strong offensive game plan is when you try to make winning connect-four formations with your chips by utilizing the chances at doing so. Try to form as many simultaneous horizontal, vertical and diagonal connections by using your disks and the opponent's disks. This will leave you with multiple win options even if one of the win options gets thwarted by the computer. The player must also ensure not to fill a slot below a game-ending move. An empty space next to a three-disk connection sometimes cannot be used due to open slots around it. It is important not to fill up these slots to create an avenue for the opponent to win the game. There are four trillion possible ways that any game of connect-4 can be played, making it impossible to remember the right moves for any given scenario. Therefore it requires practice and patience to develop the skills to win any game. Some advanced strategies can aid you in winning, such as "7" trap and the septuplet attack. The "7" trap is a configuration of your disks such that it forms the number "7" with three horizontal chips connected to two diagonal chips branching off from the last horizontal chip.

 This can be configured in many ways, forwards, backwards and upside-down backwards. The other strategy is the septuplet trap which uses a configuration that enables you to win in seven different directions, the details of which won't be discussed in this blog. The interested reader is encouraged to look this up online.

Design of connect four using MATLAB App Designer

Let us now describe an example of how the game is played. The game is initialized in the 'startupfcn' of the code where the empty board and chips are loaded, the gameboard matrix is initialized with zeros, and the result flag is set to zero. The result variable gets set to 1 for the player's win, 2 for the computer's win and 3 for a draw. The player is assigned the number '1' with red chips, and the computer is designated as '2' with the black chips. The invalid play flag is set to zero initially and gets a value of 1 when the player selects a column that is already full and will be prompted to choose an alternative unfilled column. Suppose the player chooses to start the game with column 3 and clicks on the button on top of column 3 to drop his chip down this column.

The 'playerMove' function determines the lowest possible row into which the player's chip will be placed by iterating through the rows until it finds a row just below it filled. If a column is empty, the chip lands right at the bottom, designated as row' 6'. This function is implemented with the click of a column button on top of every corresponding column. After a suitable row is computed, a red chip is placed in that slot, and the result of the move is checked. This is done with the 'checkResult' function, called within the 'playerMove' function with the input argument as the game board variable. The game board property gets set to '1' for the corresponding row and column index for the player's move and as '2' for the slots filled by the computer. The rest of the unfilled slots are zeros until occupied. This public property is declared within the properties section of the code, along with the other properties such as the 'result flag, invalid play flag and playable row as 'row'. A message is displayed to the player whether it is a win/loss/draw/none result. A message is displayed accordingly when it is the player's or the computer's turn. After the player has finished his turn, there is a small pause, after which the computer makes its move. The computer's move is designed to be such that it can identify the basic block and win moves that it keeps track of. The row-wise, column-wise and diagonal-wise win options are computed and stored, and then the computer chooses the win moves before it opts for the next best option of blocking the player's win.

If neither of these is possible, it generates a random column for its play and the bottommost unoccupied slot available is found to drop the computer's black chip into. After this, the result is checked using 'checkResult' just as before, and a message is displayed. The game alternates between the player and the computer until one connects four horizontally, vertically or diagonally. After this, the player can click on 'New Game' to start over again.

Implementation of Connect four game using App Designer

Are you looking to play #MASTERMIND? Then look no further. Here is the mastermind game built with MATLAB AppDesigner tool, which lets you play against the computer. So gear up to crack the secret color code and win the game! Challenge your friends and enter the high score table! Explore the Mastermind Game with App Designer

We also have several other blogs which uses App Designer or GUIDE, for example App Designer For Beginners, Piano Application with App Designer, etc. You should explore them and increase your MATLAB knowledge with MATLAB Helper.

Conclusion

In conclusion, Connect-4 is a classic strategy game that requires careful planning, awareness of the opponent's moves, and a combination of offensive and defensive strategies to win. The game has been solved and played using various rules and approaches, and with the development of computer technology, artificial intelligence algorithms such as minimax and negamax have become popular for solving the game. The game requires patience and practice to master advanced strategies like the "7" trap and the septuplet attack. Using MATLAB App Designer, the game can be designed with various functions, variables and conditions to initialize and play the game. Whether playing against a human opponent or a computer, the objective remains the same: to connect four chips horizontally, vertically or diagonally. Understanding these basic strategies and tactics can help players make the most of their Connect-4 experience and increase their chances of winning.