Clarence Dunner sat motionless, his shaved head tilted forward, with only the occasional twitch of his eyes hinting at the tension inside.

A few feet away, his teammates clustered, all silent and all, like Dunner, staring at the computer screen in front of him.

A slow shake of the head several minutes later was Dunner’s only acknowledgement that his opponent — some 5,000 miles away — had won the battle.

“I feel like an Olympian playing for my country. I couldn’t pull it off today,” Dunner said afterward. “But the good news is that we came in fifth. We’ve got work to do.”

On most days, Dunner and his 13 Cook County Jail teammates are indistinguishable from the thousands of other inmates in beige scrubs doing time or awaiting trial behind bars. But this week, they became superstars of sorts, competing in a first-of-its-kind in the nation online chess tournament with inmates from Russia, Italy, England, Brazil, Belarus and Armenia.

The Cook County inmates, several awaiting trial for murder or attempted murder, are the top players in an inmate chess program that began in April 2012.

“This is not just another activity in our jail . . . . This sport is transformative,” Cook County Sheriff Tom Dart said during a ceremony Tuesday that included giant flags from the participating countries and a live video link with representatives from the various prisons.

Patience, planning ahead and learning to be less impulsive are some of the benefits of playing chess, Dart said.

Like participants in an international peace treaty, men with thick Russian, English and Italian accents congratulated each other and extolled the benefits of chess.

Cook County’s program is run by Mikhail Korenman, a Russian native, who acknowledged it was always going to be tough to beat Russia, the eventual winners. Kids start learning the game there in first grade, Korenman said. And when they held a national prison chess tournament recently in Russia, 21,000 took part, he said.

During this week’s tournament, Korenman could be seen pacing inside the cinderblock room with fluorescent strip lighting where the Cook County inmates took on their international challengers. As the inmates plotted their moves on digital chessboards for games with a 15-minute time limit, the only sound that could be heard was the click of a computer mouse and the shuffle of Korenman’s shoes.

Asked if he was jittery, Korenman said: “It’s a competition. I’d like my team to win — at least to do their best.”

For the inmates, it was only partly about winning.

“This was almost like a fantasy,” said Dunner, 40, who is awaiting trial for attempted murder and has been playing chess for almost 30 years. “I’m in a dreamland right now. This is a once-in-a-lifetime opportunity. I was blessed to be a part of it.”

Inmate Brandon Lemon, 38, his face and neck smothered in tattoos, explained it this way: “It takes you to a place of relaxation. At that moment, you are free.”

And as he left the tournament room late Tuesday morning to join the rest of the jail population, Dunner said: “When I do go back into that cell, I have these memories to take with me.”