Ключевые слова: 2019, athlete, backhand, ball, billie, bulgaria, center, ceremony, championship, competition, court, dimitrov, federer, flushing, forehand, game, grand, grigor, grigor dimitrov, hard, jean, king, match, national, net, new, ny, nyc, open, player, points, practice, professional, racket, roger, roger federer, set, singles, slam, sport, sports, stadium, swiss, switzerland, tennis, tournament, training, us, us open, volley,