For me, the match of the US Open so far was Coco Gauff vs. Ajla Tomljanovic—which was also, to some extent, Coco Gauff vs. Coco Gauff. Which is why it was so compelling. Gauff is an all-world athlete and mental titan who holds two major titles at just age 21; she also happens to struggle with the two central shots of tennis, the serve and the forehand. And when those shots go awry, her matches can leave her fans white-knuckling. Sometimes a match is thrilling because of both the good tennis and the bad tennis it contains. It keeps you guessing which is coming next.

In that match on Tuesday evening, they played several of the longest and most spectacular rallies of the week, as Tomljanovic kept on the pressure with ingenious counterpunching. But lots of the pressure on Gauff was self-inflicted. You’d see her hitting an off-balance forehand off her back foot, and you’d know it’s going to land short in the court. You’d see that second serve ball toss go up, and you’d know that ball is fated for the net. In between those moments, you might also see some of the most fleet-footed defense you’ve ever seen on a tennis court. So it’s a little bit of everything.

Gauff returned to Ashe on Thursday to play her second-round match against Donna Vekic. Here her demon was, once again, the serve. She’s aware it’s an issue. In fact, just days before the US Open began, she hired the biomechanics specialist Gavin MacMillan, who had previously coached Aryna Sabalenka out of her crippling double-fault habit. Gauff was seen on practice courts receiving technical instructions, just ahead of the year’s last major. I imagine it’s a very tricky time to be in one’s head about technique. Whatever the cause, in her second-round match on Thursday, Gauff was broken four times in the first set, hitting seven double faults. She wept during the changeover after one of those breaks of serve. You might imagine that the atmosphere was tense and emotional.

I must clarify what it is actually like to sit in the lower bowl of Arthur Ashe Stadium during the night session, with beautiful, breezy late-summer weather, for a match starring the most beloved American player of the moment. All the elements are in place for an ideal tennis atmosphere. Instead the stadium is filled with an all-encompassing, dull murmur. Ten thousand lukewarm conversations taking place at the same time. The murmur continues during points, after points; it does not discriminate. It is totally indifferent to the tennis match happening below. It sounds like we are not in a stadium but rather in a large cafeteria, or hotel conference room. Sometimes the collective murmur is enough to drown out the sound of the ball. And what good is tennis without its tennis sounds?

It is the oddest atmosphere I’ve ever experienced on a show court at a tennis tournament. Even the fans seated just a few rows away from the hard court are prone to standing up, milling around, posing for photos during the rallies. I can’t remember when exactly it got this way, but it’s been like this for a while now. It feels like an unhappy medium. You get neither the pure silence of Centre Court nor the raucous environment of a normal non-tennis sporting event. You just get this purgatorial murmur. Sometimes I wonder if it’s an acoustics issue; sometimes I wonder if it’s a Honey Deuce issue. Probably a bit of both.

In any case, that’s the environment in which I watched Gauff will her way through a gutsy first set, before putting Vekic away more comfortably in the second set. And then, after the victory, and despite all my complaints I’ve just registered, Gauff started the on-court interview and…sincerely and effusively thanked the crowd. And even cried a bit! So what do I know? Maybe she’s detecting good vibes that I’ve been missing entirely. “I’ve had some tough moments on this court, and you guys pull me through each time,” she said. For the first time all night, with its teary champ on the mic, Arthur Ashe Stadium got loud.