A former tennis champion became tennis’ greatest champion as the sport moved into the Open Era. Mike Davies, a man who modernized the game – first with the World Championship Tennis league, and later as part of the Association of Tennis Professionals and International Tennis Federation – passed away last Monday at 79 years old.

The Brit modeled his game after some of the best Australian men to play the game, including Ken Rosewall, Roy Emerson, and Fred Stolle. But the Amateur Era in which he first played lacked the modern elements necessary to make tennis a twentieth century sport, so he made a then-controversial decision to turn professional. Before the Open Era began, only amateurs were eligible to play tournaments like Wimbledon and the US Open; Davies was thus barred from the tournaments he would go on to help.

A year after his playing days came to an end, he joined the team that made up the World Championship Tennis, where he worked tirelessly to make tennis TV-friendly as executive director. The yellow ball and 90-second changeovers all come back to Davies, who ushered in a golden era of the game that was bigger and better than any in the tennis world had ever seen before. In 1972, for example, the WCT final – played by Rosewall and Rod Laver – drew in 21 million viewers thanks to his TV contracts.

Davies later worked as the Marketing Director at both the ATP and ITF, reviving the former and tripling revnue at the latter – creating the Grand Slam Committee which holds court over the four major tournaments he’d been unable to play. In 2012, he was inducted into the International Tennis Hall of Fame.

“Mike was one of the true pioneers of our sport,” said WTA CEO Steve Simon. “His vision and appetite for innovation laid the foundation for the presentation of professional tennis as know it today.

“His passion and commitment will be greatly missed.”