The Open is providing a showcase for an invention by an amateur tennis player.
David Glass is a Tennessee engineer who has developed a way of measuring net cord tension.
Glass says tension varies from court-to-court and tournament-to-tournament.
He says Wimbledon is "notorious" for very loose nets.
Glass has a patent on his TNT Gauge system.
It was tested at the U.S. Open last year on two courts.
It's being used on all the courts this year.
