FILE - In this Sept. 10, 2016, file photo, Thai-Son Kwiatkowski, of the United States, serves to Austin Smith, of the United States, during the men's collegiate invitational final of the U.S. Open tennis tournament in New York. The U.S. Open will experiment during its qualifying rounds this year with scoreboard clocks to limit how much time elapses between points and how long pre-match warmups or mid-match clothing changes can last. (AP Photo/Darron Cummings, File)