It was only a matter of time.
The U.S. Open will be the first Grand Slam event to review disputed calls electronically.
... The technology will be used at the 10 U.S. Open Series events leading up to the Grand Slam in August.
The costs of using digital electronic technology to review line calls quickly has been plummeting. Meanwhile the technology has been improving over time, with the result that people tend to trust the electronic version of what happened more than they trust the line judges or the chair umpire. Result: the expected benefits of using the technology outweigh the expected costs, and it gets adopted.
But why will the tournaments use the NFL challenge-type system?
Each player gets two challenges a set to review line calls. A player only loses a challenge if the call stands. Players will receive an additional challenge during a tiebreaker, but can't carry over challenges from one set to another.
The system will be used on stadium courts, showing replays on video screens.
Why bother with challenges and guesses? Why not just programme the system to beep if shot is out?
And how much longer will it be until similar technology is used to call balls and strikes in baseball?