Chess Mathematics and computers

Chess is interesting from the mathematical point of view; the number of legal positions in chess is estimated to be between 10⁴³ and 10⁵⁰, with a game-tree complexity of approximately 10¹²³. The game-tree complexity of chess was first calculated by Claude Shannon as 10¹²⁰, a number known as the "Shannon number". Typically an average position has thirty to forty possible moves, but there may be as few as zero (in the case of checkmate or stalemate) or as many as 218.

The most important mathematical challenge of chess is the development of algorithms which can play chess. The idea of creating a chess playing machine dates to the eighteenth century; around 1769, the chess playing automaton called The Turk became famous before being exposed as a hoax. Serious trials based on automatons, such as El Ajedrecista, were too complex and limited to be useful.

Since the advent of the digital computer in the 1950s, chess enthusiasts and computer engineers have built, with increasing degrees of seriousness and success, chess-playing machines and computer programs. The groundbreaking paper on computer chess, "Programming a Computer for Playing Chess", was published in 1950 by Shannon. About the future possibilities of newly-born computers, Shannon wrote:

The chess machine is an ideal one to start with, since: (1) the problem is sharply defined both in allowed operations (the moves) and in the ultimate goal (checkmate); (2) it is neither so simple as to be trivial nor too difficult for satisfactory solution; (3) chess is generally considered to require "thinking" for skilful play; a solution of this problem will force us either to admit the possibility of a mechanized thinking or to further restrict our concept of "thinking"; (4) the discrete structure of chess fits well into the digital nature of
modern computers.Shannon, Claude E. XXII. Programming a Computer for Playing Chess. Philosophical Magazine, Ser.7, Vol. 41, No. 314 - March 1950. Available online at computerhistory.org (PDF).

The Association for Computing Machinery (ACM) held the first major chess tournament for computers, the North American Computer Chess Championship, in September 1970. Chess (Northwestern University)CHESS 3.0, a chess program from Northwestern University, won the championship. At first considered only a curiosity, the best chess enginechess playing programs, for example Rybka or Hydra (chess)Hydra, have become extremely strong. Nevertheless, from the point of view of artificial intelligence, chess-playing programs are relatively simple: they essentially explore huge numbers of potential future moves by both players and apply an evaluation function to the resulting positions.

Garry Kasparov, then ranked number one in the world, played a six-game match against International Business MachinesIBM's chess computer Deep Blue in February 1996. Deep Blue won the Deep Blue - Kasparov, 1996, Game 1first game, but Kasparov convincingly won the match by winning three games and drawing two. The six-game rematch in May 1997 was won by the machine (informally dubbed "Deeper Blue"), which was subsequently retired by IBM.

With huge databases of past games and high analytical ability, computers also help players to learn chess and prepare for matches. Additionally, Internet sites such as Free Internet Chess Server and Kurnik allow people to find and play opponents all over the world. It is estimated that more than 285 million people play chess via the internet today. The presence of computers and modern communication tools have also raised concerns regarding cheating during games, most notably the "FIDE World Chess Championship 2006#Bathroom controversybathroom controversy" during the 2006 World Championship.
Source wikipedia