The World Chess Championship is heading toward a dramatic conclusion on Wednesday, which could give the U.S. its first champion since Bobby Fischer took the crown in 1972.
The players will embark on a series of fast-moving tiebreaks at the event in London, which will get faster and faster if they continue to draw.
Fabiano Caruana, the 26-year-old Italian-American prodigy who grew up in Brooklyn, is definitely the underdog. For 12 games so far, he has taken on the current world chess champion, Magnus Carlsen. And each game has ended in a draw.
"I've had mediocre years, I've had good years," Caruana said in a recent interview with The New York Times. "This year has been the best by far."
According to the organizer World Chess, it's the first championship match where nobody has won a game through the first 12 games of regular play.
Carlsen, who is 27 and from Norway, has been on top of the game for much of his adult life. He's held the world champion title since 2013.
But some observers think he may be losing his edge. "He's a shadow of himself, of his best times," chess grandmaster Judit Polgár tells NPR's Here & Now.
Carlsen raised eyebrows at a crucial moment in Game 12, when he appeared to be in a stronger position, yet suddenly offered to leave the game as a draw.
"For whatever reason, he chose not to invest the energy and, instead, proposed a draw after 31 moves, which Caruana accepted," according to a write-up from World Chess.
That decision was baffling to legendary chess grandmaster Garry Kasparov.
"In light of this shocking draw offer from Magnus in a superior position with more time, I reconsider my evaluation of him being the favorite in rapids," Kasparov wrote on Twitter. "Tiebreaks require tremendous nerves and he seems to be losing his."
At the same time, World Chess pointed out that even though computer calculations say Carlsen was more likely to win when he offered the draw, "the position was complicated and it was clear that it would take a lot of maneuvering, and many hours, if Carlsen hoped to break through."
"I wasn't in a mood to find the punch," Carlsen said after the game, according to FiveThirtyEight.
Polgár said Carlsen has previously been known for avoiding draws. She says the two players are very evenly matched. "I think he lost the appetite of winning, or it is not so much important for him to win again, somehow he cannot motivate himself so much as he could before," she said.
These past 12 games have been played according to time regulations that mean each game can take hours. The players have 100 minutes each for the first 40 moves, with even more time added after that.
But on Wednesday, the pace of the game is going to speed up – a lot. The challenge of the tie-breaks is that play happens in smaller and smaller amounts of time.
The faster play is expected to work in Carlsen's favor. He's higher-ranked in styles of chess with tighter time regulations.
The first four tie-breaker games start with 25 minutes each on the clock, and 10 additional seconds after each move.
After those four games, if the scores are still tied, it moves to even faster rounds called "blitz games."
First, the players play two games with five minutes each plus three seconds after each move. If they're still tied, they'll play another two games, and this could continue up to 10 games total.
And if it's still even after the end of the blitz games, they'll go to a round referred to as "Armageddon."
The player who has white pieces gets five minutes on his clock, one more minute than the player who has black. But, should the game end in a draw, the player with black pieces is automatically the winner.
And unless the referee decides otherwise, according to the rules, the players will have just 10 minutes between each of these tie-break games.
Besides the coveted title of world champion, there's a lot of money on the line. The players are duking it out for a prize fund of 1 million euros ($1.1 million). If it had been decided in regular games the winner would get 60 percent and the loser 40 percent — now, because it has gone to tie-break games, the winner will get 55 percent and the loser 45 percent.
It's worth noting that it's highly unlikely that the matches will actually get to the epic conclusion of a sudden death round.
In fact, according to calculations by FiveThirtyEight, there's a 0.02 percent chance this World Chess Championship will end in Armageddon.
We'll just have to watch to find out. Games kick off Wednesday at 10 a.m. ET.