Inside the intense, sometimes quirky chess rivalry between Magnus Carlsen and Fabiano Caruana

World champion Magnus Carlsen, left, of Norway, is known as the golden boy of chess. Now, world No. 2 and U.S. challenger Fabiano Caruana has a shot at the title at the World Chess Championship. Neeta Satam for ESPN

ST. LOUIS -- Three hours into the most intense match of the 2018 Sinquefield Cup between chess world champion Magnus Carlsen and world No. 2 Fabiano Caruana, something strange happened.

Carlsen, who looked as though he was cruising to a victory over the American, put on his jacket, glared at the board and then his opponent, and walked to the confession booth -- a small room where players record videos that are played live for the fans. The 27-year-old looked directly at the camera and placed his index finger on his lips.

"Shhhhh," he said, evidently taunting Caruana and his enthusiastic fans at the Saint Louis Chess Club on this August day.

Chess players usually play nice. They sometimes record videos talking about their game, their opponent's performance and where they think a tournament is headed. They don't usually goad their rivals.

Then again, Carlsen isn't an ordinary chess player. He has been the world champion since 2013 and is considered the king of all chess players. The Norwegian knows he is a genius -- and he flaunts it.

But his rival isn't ordinary, either.

Caruana is close -- really close -- to snatching away Carlsen's title at the World Chess Championships, set for Nov. 9-28 in London, and their matchup in St. Louis was a peek into what might play out in England. There has never been a match for the world title between players so closely ranked. As of Nov. 1, Carlsen led by only 3 points. And Caruana has had a monumental year: He's not only stopped Carlsen from winning matches, but he's also won tournaments in which the champ was also entered. In March, Caruana won an important tournament -- an eight-player round-robin in Germany -- earning the right to challenge Carlsen in the World Championships. He's being called the next Bobby Fischer, after the American grandmaster who was responsible for revolutionizing chess in the U.S. after his 1972 world championship victory.

"Fabi is having an insane ... I don't even know what it is he is doing, he is winning everywhere," said Viswanathan Anand, former longtime world champion. "Magnus is getting a little bit wobbly, I have to say."

An hour after Carlsen's message in the confession booth, it almost felt as though the roles had reversed. Caruana began to dominate, and Carlsen was on the run. The match ended in a draw. Had he lost, Carlsen would have relinquished his world No. 1 title to Caruana.

Carlsen, who was once untouchable, looks vulnerable, especially in the past few months, losing to other grandmasters in regular tournaments. So much so that when asked who's the favorite to win in November, Anand said, "I have to say it's looking like 50-50 at the moment."

Said Caruana after the tournament: "[Magnus] has been trying to put me under pressure, and he has been trying to beat me, but I am also just as motivated."

It almost feels as though Carlsen is chasing Caruana this year, Anand said. He wants to put Caruana under pressure and prove to himself that he can still win before November. And that usually happens when a grandmaster is not playing the best chess.

"That kind of backfired," Carlsen said later of his confession-booth stunt. "I was absolutely sure I was winning." He also admitted he was nervous before the Sinquefield Cup match -- and Carlsen is never nervous.

Caruana smiled when he finally saw the video: "I guess he thought it was already over, but it wasn't," he said.

Ask any chess fan and they'll tell you this: Magnus Carlsen and Fabiano Caruana aren't very fond of each other. The day before the tournament, Caruana and Carlsen were seated next to each other during an autograph session. A fan walked toward them, and as Caruana was getting ready to sign his poster, the fan walked directly to Carlsen. "I am a huge fan of yours. There is no way you're going to lose this November," he said loudly to Carlsen. Carlsen smirked and signed his poster. Caruana's face fell, ever so slightly. Some thought this was a setup on Carlsen's part; he is known to play such mind games.

And even ceremonial interactions seem strained. Right before Round 7 of the Sinquefield Cup, while the eight other grandmasters were making friendly small talk, the pair stared stoically at the chessboard, avoiding eye contact. Their mandatory handshake lasted exactly half a second, and it was exactly that -- an obligation.

For most of their rivalry, Carlsen has been the golden boy. It was like the universe had created a path to stardom, and he was walking the path. He fulfilled all of his promises, even overdelivered. Ever since he became grandmaster at age 13, nobody could touch him. He would go on to beat Anand, the dominating world champ, in 2013 and hold three world titles simultaneously.

It also didn't hurt that fans loved his scruffy brown hair and his flamboyant personality. He made appearances in "The Simpsons," he modeled for clothing brands, he was named one of Cosmopolitan's sexiest men of 2013 and he was the subject of the 2016 documentary "Magnus."

"Magnus Carlsen was meant to be the best, and he knew that," grandmaster Maurice Ashley said. "It was the natural order of things."

Caruana was only about two years younger, but he was always in Carlsen's shadow, always had to claw his way even to be considered one of the top contenders. In the 56 matches they've played against each other, Carlsen has won 22 times, Caruana has won 12 and they've drawn 22. In other words, Carlsen was always a step or two ahead.

And while Carlsen loved the spotlight, Caruana let his game speak for him and didn't actively build his brand. He was a mellow guy from Miami, who loved sushi, horror movies and video games -- and was incredibly passionate about chess. After his first organized chess class, his teacher told his parents, Santina and Lou Caruana, "The only problem I have with Fabiano is that he doesn't want me to teach him, he wants to teach me." Twenty minutes into his first meeting with a 5-year-old Caruana, chess guru Bruce Pandolfini said to Santina and Lou, "I have never seen a child with this kind of understanding of the game like your son has -- it's the way his eyes move across the chessboard."

While Carlsen was making news, Caruana quietly moved to Europe with his parents. First to Spain, and then to Budapest, Hungary, to train with the best in the sport. He became a grandmaster a year after Carlsen, was homeschooled and traveled the world for tournaments. At every hotel room they stayed in, Caruana's dad had a ritual: He would walk into the room with his compass, figure out where the sun was going to rise and move the bed so the sun wouldn't wake his son up at the crack of dawn and mess up his schedule. After 10 years in Europe, Caruana, who is also an Italian citizen, made the decision to move back to the U.S.; America was home and he wanted to represent his home. By 25, he was the owner of two houses -- one in Miami and the other in St. Louis, where he now lives -- judiciously spending his chess earnings for his future.

Even though his coaches recognized his talent, they knew Caruana would take his time to get to the top. He was a thinker, an analyzer, and that would take time to translate to wins.

"Although Carlsen has an edge on Fabi from the very beginning," Ashley said, "that edge has eroded to now when you see the two of them, you think, 'Magnus might be a little better, but it's not clear who is going to win,' or you can't just say, 'On any given day, Magnus is just going to beat this guy,'".

On the first floor of the Saint Louis Chess Club, fans congregated after the "Super Saturday" matchup between Carlsen and Caruana. A 10-year-old held a notebook, an older man carried a picture album of chess players, an elderly lady clutched her portable chair in her hand. They were all waiting for Caruana to come back from the media room; they all wanted autographs or photos.

Caruana walked out of the club and looked around. Casual fans played chess on the tables outside; tourists took pictures with the 14-foot chess piece at the Chess Hall of Fame across the street; club members were enjoying half-off burgers at the Kingside Diner next door. Walking two more blocks, he faded into the St. Louis crowd. Nobody gave him a second look.

Caruana has enjoyed relative anonymity for most of his life. He's famous, but only within the walls of the chess club where he's playing at any given time. But that might change come November. The marathon 12-game match with Carlsen will test him. If Caruana wins early on, Carlsen will spend the rest of the tournament playing catch-up. If it ends in a tie and they have to play a tiebreaker -- blitz chess -- Carlsen, a master at speed chess, will have a clear edge. But if Caruana becomes the world champion, he will ascend to a new level of famous -- the first American to win a world championship since Fischer in 1972.

And like Fischer, Caruana could invigorate a new generation of chess players in America.

"My dream is that Carlsen's era finishes," Santina Caruana said, "and Caruana's era begins."