Wesley So had a confession to make.

The grandmaster from Minnetonka had violated virtually every opening principle in the game just to win a pawn. He’d left himself vulnerable to a swift counterattack.

While his opponent was trying to figure out if a trap had been laid, So stepped away from the chessboard into a soundproof room outfitted with a video camera. There, speaking to an audience watching online, So admitted that there was no plan, that he’d just messed up.

The “confessional booth,” where the world’s top players reveal their strategies or errors during a live game, is one of the innovations that chess promoters are using to adapt the ancient game to modern entertainment. They hope they can make chess the new poker, winning fans — and, ultimately, TV coverage.

Trying to replicate the successful World Poker Tour, a new event is marketing chess to the masses. The year-old Millionaire Chess Open is dangling huge cash prizes for everyone from grandmasters to club players. Purposefully set amid the sizzle and flash of Las Vegas, the high-stakes event is designed to capture the attention of wide audiences, along the lines of “American Idol” or “So You Think You Can Dance.”

“It’s about creating enough dynamic energy around the event that sponsors see something big is happening,” said Maurice Ashley, the brains behind the Millionaire Chess Open, which will soon hold its second tournament.

Although Ashley concedes that selling chess to TV executives is “maybe just as hard as some people said it would be,” it’s coming at a fortunate time, because the U.S. chess scene has a crop of young, exceptionally talented and even telegenic young stars.

The country boasts three players among the top 10 in the world — more even than Russia, where chess remains a revered game. And U.S. Chess Federation membership is at near record levels, with about 85,000 dues-paying players.

Ashley, the first African-American grandmaster, has become the most visible promoter of chess in the United States. He teamed up with Amy Lee, an entrepreneur who made her millions in a dollar-store chain, real estate development and other ventures, to create the Millionaire Chess Open, which guaranteed a $100,000 prize to the overall winner, and prizes in the tens of thousands for winners of lower divisions. To have a shot at the big payday, though, players have to take a Vegas-style gamble by plunking down an entry fee of at least $880.

Millionaire Chess Open’s launch last year drew lots of media attention. This year, the event is upping the ante by adding a game-show element: In addition to cash prizes, one lucky player will get a chance to pick from 64 envelopes — one on each square of a giant chessboard. One of those envelopes will contain $1 million.

The biggest beneficiary of the effort to elevate chess from nerdy to flashy has been So, who took home the $100,000 grand prize at the inaugural Millionaire Chess Open. That nest egg helped him quit college, move to Minnetonka and launch a career as a chess professional.

“People in the U.S. didn’t used to understand soccer,” he said. “Because of media involvement, it now has an audience. … Media exposure draws all kinds of new fans to poker games, golf, pingpong, cooking, gardening.”

John Bartholomew of Eagan is another Minnesota player who’ll be returning for the Millionaire Open’s second year. But Bartholomew, an international master who makes a living by teaching and playing chess, said he is doubtful that chess can match poker’s draw.

“Chess has always had trouble with that, expanding its reach beyond chess players,” he said. “It’s hard to market it to people who don’t play.”

Poker gives viewers a peek at the cards each player holds, which offers dramatic uncertainty over the next card that will be flipped. “In chess, the answers are in the players’ heads,” Bartholomew said.

Chess would need “some sort of seismic shift” to make the leap to the mainstream, he said. But that shift could be in the offing.

Next year, world champion Magnus Carlsen of Norway will have to defend his title. His challenger will be the winner of an eight-player “candidate’s tournament.” Already, two Americans — Fabiano Caruana and Hikaru Nakamura — have qualified for that playoff.

An American playing for the world title — for the first time since Bobby Fischer won it in 1972 — would create a stir and might garner live TV coverage like Fischer’s match did. Having a new movie about Fischer (“Pawn Sacrifice”) in theaters across the country doesn’t hurt.

Meanwhile, Ashley said he’s gotten nibbles of interest from TV producers. As he wrote in a recent newsletter, “It’s an exciting moment for our royal game.”