The US Open tennis championships begins on Monday, but too late for a revolutionary new device which promises 100 per cent accuracy on line calls. A sensor embedded in the ground will register the ball hitting the line, and linesmen equipped with ear-phones will hear a signal when the ball is in.

The spectators will also be able to see the results on large television screens, according to the tournament director of November's Stockholm Open where the device will operate for the first time.

Prepare for some hiccups. Remember Ile Nastase when Wimbledon first introduced their magic box along the service line?