1) 145
2) 139
3) 141
4) 143
Explanation:
US Open 2019, annual hard-court tennis competition, was held from August 26- September 8, 2019 at USTA Billie Jean King National Tennis Center in Flushing Meadows–Corona Park, New York, United States (US) on 14 DecoTurf hard courts. It was the 139th edition of the tournament which was run by the International Tennis Federation (ITF) and was a part of the 2019 Association of Tennis Professionals (ATP) Tour and the 2019 Women’s Tennis Association (WTA) Tour calendars under the Grand Slam category.