In England we tend to associate tennis with the couple of weeks at the end of June when Wimbledon is transformed into the shrine of a sport invented over 100 ago by Major Digby Clopton and originally sold as Spairistike - a polite game to play on the lawn with friends on a summer afternoon. Little did he realise that over 100 years later, his game would grow into a vast industry that tours the world, commands megabuck salaries for its leading players and turns them into sporting icons.