Thursday, August 16, 2007

How good is your computer at playing chess?

The history of computers playing chess dates back to 1914 when the first real chess playing machine called El Ajedrecista built by Leonardo Torres y Quevedo made its debut during Paris World Fair. I say real because prior to that several unsuccessful attempts were made to create chess playing machines using cunning tricks like hiding a man inside the machine! The most famous being the machine called the Turk, unveiled in 1769 by Wolfgang von Kempelen, at the court of Empress Maria Theresa. After the advent of digital computers in the 1950s, chess enthusiasts and computer engineers have built, with increasing degrees of seriousness and success, chess-playing machines and computer programs. In 1997 computers made history when Deep Blue of IBM defeated world chess champion Garry Kasparov, and the general outcome was that the strongest player in the world is a computer.

There are two strategies that a computer chess program employs

1. Type A programs uses a "brute force search" approach, examining every possible position for a fixed number of moves.
2. Type B is relies on the program being able to decide which moves are good enough to be worthy of consideration ('plausible') in any given position.

The problem with type B is that computers are bad at deciding which is “good”. ;) The result was that Type A became the most used technique in chess programs.

A computer’s ability of playing chess is measured by its capacity of calculating chess moves. The unit used is KiloNodes per Second (kN/s). 1kN/s is equal to 1000 chess position per second. I used the Fritz Chess Benchmark to benchmark my PC, a Pentium D 2.8GHz. The result is 1613 kN/s which is approximately 1.613 million chess positions per second. That’s tiny if you compare it to Deep Blue’s which stood at 200 million chess moves per second! Wow! Download the program and benchmark your PCs too.

Here is a list of processors and their respective chess marks; the fastest is the 8 core Intel Xeon X5355 which manages 12345 kN/s or 12.345 million chess moves per second. Now you know what it took to beat Gary Kasparov.

Wikipedia: Deep Blue
Wikipedia: Computer chess
Project Deep Blitz: Chess PC Takes on Deep Blue


  1. Thanks for the definition of kN (kilonodes).

  2. Fritz 8 is stronger than DeepBlue or DeeperBlue.As Topalov said,KAsparov's match with IBM's machine was a setup.


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