A 17-year-old chess grandmaster was charged with assault and expelled from a championship tournament after he hit a woman when he lost a match in St. Louis last week, officials said.
Christopher Yoo "crumpled his scoresheet, stormed out of the tournament hall and struck a videographer from behind" after he lost a U.S. Chess Championship match at the Saint Louis Chess Club last Wednesday, the club said in a statement on X.
A video released by the Saint Louis Chess Club shows Yoo crumpling his scoresheet after the loss to now-four-time U.S. chess champion Fabiano Caruana. The video does not capture the moment Yoo struck the videographer.
The club said it "immediately provided assistance to the videographer and called the police who responded."
Yoo was charged with fourth-degree assault before he was released to one of his parents at the direction of the juvenile courts, St. Louis police told NBC News on Thursday.
Yoo was expelled from the tournament because of "gross violations" of its code of conduct and the U.S. Chess Safe Play Policy, the statement said. He has since been banned from the Saint Louis Chess Club.
The club decided to annul Yoo's results from rounds 1-5 of the competition and adjust tournament standings accordingly, meaning competitors scheduled to play him would get an additional rest day.
Yoo has since issued an apology that was posted on the U.S. Chess Federation website and his parents' Facebook page Monday.
"I am really sorry for hitting the videographer. I was disappointed losing the game to Caruana and lost my temper. That’s no excuse, I know," he said. "It was a serious mistake. Every day I wish I could go back in time and undo it, but I can’t."
Yoo said he accepted the consequences for his actions and promised it wouldn't happen again. He also said he hoped the videographer was OK.
"All I can do is to be better from now on," he wrote. "Best of luck to Caruana. I am sorry this happened after our game. And best of luck to the other players and best wishes to the St. Louis Chess Club."
Above Yoo's apology, his parents wrote, "Christopher is not good with words and expressing emotions, but his remorse is very real."
In a post they shared on Facebook three days earlier, Yoo's parents said their son wanted to "publicly apologize to the female videographer that was an innocent victim of his anger after his loss of a chess game," adding that she "did nothing to provoke Christopher."
They also said Yoo is "very sad and ashamed he behaved in that way" and "offers no excuses for his behavior."
The post said Yoo "tearfully" apologized to the executive director of the club and sent the videographer a personal apology.
"Many people have expressed concerns about the mental well-being of our 17-year old son. As parents we more than share their concern," the post added. "Something like this has never happened before and he will be getting therapy to help make sure his mental well-being is properly cared for and that something like this will not happen again."
Yoo became the youngest American master at age 9 in 2016 and the youngest international master at 12 in 2019, until Abhimanyu Mishra beat his record.
He won the 2024 U.S. Junior Chess Championship, which earned him his spot in the U.S. Championship.