Literature Survey of Chess Engines Anushka Nair Department of Computer Engineering, Atharva College of Engineering. Mumbai, India. Kanksha Marathe Department of Computer Engineering, Atharva College of Engineering. Mumbai, India. Prof. Suvarna Pansambal Department of Computer Engineering, Atharva College of Engineering. Mumbai, India. Abstract - Chess has come a long way since making its appearance on a computer and every year there is a new chess engine created that works better than the previously existing ones. But all these engines have one thing in common, they all work on some variant of the MinMax algorithm. The game tree is made shorter and more efficient and ways to play around with the graphical user interface are invented. The search tree is then pruned to save the time that the machine needs to compute the next best move. Thanks to all this, chess engines have come a long way and are now known all around the world to defeat some of the best Grandmasters of the world with their own strategies. But the AI in chess still has a long way to go before it can be declared as the fastest and the best chess playing machine. Keywords: Chess, Engine, MinMax Algorithm, Pruning. I. INTRODUCTION This paper focuses on not only the software part of the engines discussed here, but also advancements in the hardware and graphical user interface of a chess engine. Since most engines use a variant of the MinMax search tree, it is considered as an efficient algorithm for running the engine. Each variant is then improved using new searching or pruning techniques. The hardware is updated accordingly to help the machine carry out the calculations faster. The GUI is improved using various tools available. Making the GUI interactive makes the user feel more and more close to playing the actual game but at the convenience of portability. 2D as well as 3D graphics and other media like background sound is added to give the game a little bit of personality and edge over the original orthodox game. Also, now more and more variants of the game itself are being made to attract the number of players of chess. The Surakarta chess and the hexagonal chess are some of the better known versions that are gaining popularity amongst players of the game. These engines work on the same idea except the chessmen move in ways different to the original chess. The board is also constructed in a different way to give players the feeling of playing an entirely different game. Each engine is constructed keeping in mind that it should run on the average machine and no extra processing units should be needed unless it is required for computing a very complicated game tree or adding very high definition graphics to it. Also, a lot of games are made purely to be played on a network between two connected client machines, which means players can play against each other or the computer. II. DEFINITIONS 1. MinMax Algorithm: is a decision based rule used in a game tree for minimizing the loss for a worst case scenario. Originally formulated for two-player zero- sum games like chess, it has evolved into various variants to work in more complex versions of chess as well as other games. 2. Pruning: In a game tree, when the minimum node or the maximum node is already the value it needs to be and further traversing is not required, then that particular branch of the tree is pruned or cut off from the traversal. 3. Surakarta Chess [5]: This is a Chinese version of battle chess where the square chessboard has six horizontal lines and six vertical lines. On the thirty- six crossing points of horizontal lines and vertical lines are chess pieces. All these lines are linked by eight arc lines. Each side to play the game has twelve chess pieces. 4. Hexagonal Chess: In hexagonal chess, the board is in the form of a hexagon with 91 cells. The best known is Gliński's variant, which is a symmetric hexagonal board. The rules and movements of the chessmen vary according to the maker. III. LITERATURE SURVEY Murray Campbell et al [1] contributed in the making of this chess engine which was attempted twice because the first time it lost to the chess grandmaster Garry Kasparov in 1996 but later went on to defeat him in 1997. It was the first chess machine to defeat a grandmaster in tournament play. It uses a single chip move generator. Deep Thought 1 and Deep thought 2 were intermediate stepping stones to the Deep Blue, but Deep Thought 2 was played in a lot of public events from 1991-1995. Deep Blue I, which was initially defeated by Kasparov, made it International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Published by, www.ijert.org ICIATE - 2017 Conference Proceedings Volume 5, Issue 01 Special Issue - 2017