Conclusions

Monte Carlo Tree Search appears to be a good solution compared to the other more naive approaches to solving board games such as MiniMax while bing easier to implement than more in depth solutions such as Neural Networks. Monte Carlo Tree Search is able to search more moves than MiniMax even when MiniMax has improvements such as Alpha Beta to cut down on the number of different paths that the function has to evaluate. However, even with this improved speed, without extra help to improve its play such as an opening book or specific knowledge about certain patterns it will still have trouble with better opponents unless given a large amount of time to study the given position. Monte Carlo Tree Search is also able to scale up a lot better when given a much larger search space when I compared the two algorithms on the larger 13x13 and 19x19 boards as Alpha Beta Minimax is too slow in this scenario to be able to evaluate the position correctly as it has to play out all possible move states where as Monte Carlo Tree Search tries to only look at the best possible moves as much as possible. If both of these algorithms were given adequate information on opening ideas as well as different common positions that could arise in the game, I could see that Monte Carlo would still perform a lot better on the bigger boards but it would stay a bit more even on the smaller boards where Alpha Beta is able to search through a lot more of the available moves.

Future Work

There is still some room to add extra parts to both the Monte Carlo Tree Search as well as the Alpha Beta to try improve both their speed in finding a good move as well as how they evaluate positions. Zobrist Hashing could improve the speed for both of the algorithms as this could save a lot of time in terms of each of the algorithms re-evaluating previously seen positions. Zobrist hashing allows the algorithms to store a hash for a certain board position along side the generated score for the position so that if it is encountered again you can use this score instead of having to re-evaluate. This can lead to problems in terms of figuring out a good hashing algorithm as to lead to as few collisions as possible, i.e. two different positions getting the same hash which could worsen the algorithms as they could misinterpret a position. How to store all of the different positions alongside their scores also needs to be taken into consideration as look up as well as inputing positions should be as fast as possible to make sure that this is faster than the regular algorithms while also making sure it does not use up too much memory. The algorithms could also be given more domain specific knowledge to try and give them a better edge in determining how to play certain positions as at the moment they may not notice common problems appearing on the board. I would also try to look into other parts of machine learning such as reinforcement learning to see how much a reinforcement learning model could improve the outputs of moves. This would require a lot more resources in order to train as well as to make sure works as intended, but hopefully once trained fully, would lead to better play than the other two approaches mentioned as it can train on a large amount of professional games whereas the other algorithms are just playing based on a custom evaluation function. This could also help with the algorithms not understanding different problems found on the board such as when certain pieces are alive as well as protecting their own pieces and territory better. One next step could be to further compare different types of machine learning against each other for trying to solve the game of go. One area that would probably be best to focus on would be supervised learning. A component ai could be created given a good data set to train the model on, however this could take a while to train the agent so some way of speeding this training up using multiple pcs or a different technique to use alongside the supervised learning would be needed. This would be similar to some of the ai that AlphaGo created as they were creating their neural network where they used a large number of professional games to try and create an ai that could play the game as well. Other games could also be chosen to see how these algorithms could be used in those games. Chess may be an easier game to create an AI for as the search space is a lot smaller, however it could take a bit longer to actually implement the game itself into an environment that you could use unless you use a pre-made one as the rules of Go are not as complex. For my implementation of the model, I did not use any external data apart from training it on playing the actual game, so giving the ai an opening book as well as puzzles as part of some kind of Supervised learning could improve the skill level of the ai that are generated as the skill level of the ai that I generated is not that high, especially for the larger boards as this is a much harder problem to solve, so someone could first try to make a good ai for the smaller boards and then work up to creating an ai that can play reasonably well compared to a human beginner at the game. My game was created without being able to also be used to play against ai created by other players. There is a standardised format for playing moves on a board as well as a way to format boards that could be used to also incorporate other ai into the game which could then be used to compare the ai against already created ai if needed.