Played by humans, chess is a game of strategic thinking, calm concentration and patient intellectual endeavour. Violence does not usually come into it. The same, it seems, cannot always be said of machines. Last week, according to Russian media outlets, a chess-playing robot, apparently unsettled by the quick responses of a seven-year-old boy, unceremoniously grabbed and broke his finger during a match at the Moscow Open. "The robot broke the child's finger," Sergey Lazarev, president of the Moscow Chess Federation, told the TASS news agency after the incident, adding that the machine had played many previous exhibitions without upset.