Who is the best? Well, it depends who you ask.

For super fan Yerbolat Kabulov, the answer changes from day to day, and normally several times each day.

Kabulov — who goes by his easier-to-pronounce nickname Ali — has become something of a viral sensation at the 2018 US Open, popping up everywhere across the grounds of the USTA Billie Jean King National Tennis Center -- from the sidelines of the outer courts to the promenade level in Arthur Ashe Stadium.

The idea for Kabulov is simple. Find an underdog or a relatively unknown player from a small country that doesn’t have any support, then insert their first name into the question-and-answer chant, “Who is the best? Player X is the best!”

“Small country, underdog, young girls, no nickname,” said 39-year-old Kabulov, who is attending the US Open for the fourth year. “Famous superstars have lots of fans.”

On Wednesday, Radu Albot from Moldova was the best, at least during one point. The following point, Albot’s doubles partner, Malek Jaziri of Tunisia, was the best. As soon as Albot and Jaziri upset 2016 US Open doubles champions Jamie Murray and Bruno Soares in the Grandstand, Kabulov sprinted through the South Plaza and into the front row of section 332 in Ashe just in time to proclaim that Lesia Tsurenko was the best in the closing moments of her eventual quarterfinal loss to Naomi Osaka.

"I support only the underdog. I give mental power. Keep fighting. Never give up.”

Kabulov could be heard Tuesday supporting Mariam Dalakishvili of Georgia on Court 7. Later in the afternoon, Viktoryia Kanapatskaya of Belarus and Selma Stefania Cadar of Romania received his passionate support in the first round of the girls’ doubles on Court 13. Kanapatskaya and Cadar could be seen laughing between points and covering their mouths with their hands as they were getting ready to return.

On Monday, Kabulov, a delivery and logistics worker from California who was born in Pavlodar in northeastern Khazakhstan, cheered for Ukrainian junior qualifier Daria Snigur. Over the weekend, it was Ukrainian 15-year-old Dasha Lopatetskaya and Karolina Muchova and Marie Bouzkova from the Czech Republic. In Week 1, he got behind another Georgian, Nikoloz Basilashvili, the overwhelming underdog who took a set off Rafael Nadal in Ashe, and Elina Svitolina, who fell to Anastasija Sevastova.

"I think he's, like, walking around and yelling for everyone," Sevastova said after the match. "He can yell for everybody. I don't care. It's okay. I heard it in the Ostapenko match yesterday. It was the same cheer, so ... he likes to cheer."

His cheers — loud, enthusiastic and somewhat repetitive — have received largely positive reviews. Most people are entertained by his cheering, even though he has received glares from chair umpires who have asked him, in the nicest way possible, to save his cheering for the conclusion of points.

“They enjoy, they’re laughing,” Kabulov said of the reaction from players. “More support. Psychology punch for the opponent. Tennis is mental game.

“Some people support, say ‘Good, good.’ I support after points. Another game a referee say, ‘Hey, stop, not in between.’ If opponent lost, sometimes coaches cry, goes to referee, security, ‘We lost because of this guy.’”

Kabulov has been at the US Open every day from the start of the US Open Qualifying Tournament, which was free to attend. Once the main draw started on Aug. 27, he’d only buy a ticket for Arthur Ashe Stadium if there was a young, relatively unknown player facing a star. If there were no players from small countries scheduled to play in Ashe that day, Kabulov would either buy a ticket for Louis Armstrong Stadium or purchase a grounds pass – both options allowed him access to every field court, plus Court 17 and Grandstand.

 

“I started supporting my team Kazakhstan at Davis Cup, Fed Cup. I know all Kazakhstan team players,” said Kabulov, tracing his roots of tennis fandom to the international team competition. Since that introduction, he’s also attended the Miami Open three times and Indian Wells twice, every time pledging his allegiance to the players whom he believes deserve his support the most.

“Today, I say ‘Lesia the best. Ukraine never give up. Never. You play for your country, keep going. I’m here.’ Whole stadium, maybe 40 percent Japanese people. I support only the underdog. I give mental power. Keep fighting. Never give up.”

When he’s not at the tennis court, Kabulov devotes his time to another sport that requires mental strength: chess.

Kabulov, who splits time between San Francisco and Seattle, travels to watch pawns, rooks and queens battle for supremacy at tournaments in St. Louis, North Carolina, Idaho, Denver and Las Vegas with Uzbekistani friend and chess Grandmaster Timur Gareyev. Kabulov's stories of criss-crossing America with Gareyev provide a totally random non sequitur in an otherwise light-hearted discussion about tennis fandom.

But Kabulov says it’s important to support young players in small countries in every sport, not only chess and tennis, to show children that it's possible to reach the biggest tournaments in the world, regardless of where you were born. He's passionate about both sports and he's doing his best to cheer on the underdog whereever he goes.

“[Players] from Ukraine, from Moldova, from Kazakhstan, from small countries. People think, ‘Whoa.’ They see. Don’t give up.”