Hoping to forget last year's U.S. Chess Championship tournament, where things went wrong for him on and off the board, Minnetonka Grandmaster Wesley So got off to a smashing start in the first round of this year's championship ­Thursday.

So demolished his opponent in a short game that featured a piece sacrifice to rip open the protection around his opponent's king, forcing resignation a handful of moves later.

The game was hailed by chess experts for the ease in which So took down Grandmaster Gata Kamsky, who is a five-time U.S. champion and once played in a world championship match. A Chess24.com article said So made it "look like child's play!"

Last year was the first time So competed for the U.S. chess title, but he faltered after an unexpected visit from his estranged mother, and an inkling that a former coach was plotting against him contributed to a rules violation forfeit and subpar play.

In the year since that tournament, So has had ups and downs — finishing last in one elite tournament and winning another that included a former world champion in the field. Through it all, though, So has consistently held his spot among the top 10 players in the world.

After his win Thursday, So answered a question often put to grandmasters about how many moves ahead they can see. In this case, So explained, he didn't calculate all the possible variations arising from the sacrifice. He used intuition to decide, after only 5 minutes and 34 seconds of thought, that giving up the knight for a pawn would eventually be to his advantage.

"I don't think I would be a professional chess player if I tried to calculate everything," he said after the game. "I would get too much of a headache."

Though So is off to a good start this year in the tournament in St. Louis, there are still 10 rounds to go. And while So is ranked No. 10 in the world, two players ranked higher also are playing in the tournament, making So only the No. 3 seed. The U.S. has so many strong players that this year's national championship is considered the second toughest in the world, after Russia's.

With a rest day after the fifth round, the tournament will conclude on April 25, barring the need for a tiebreaking playoff.

The winner will take home a $50,000 prize.

Analysis of So's win and the other first-round games can be found at Chess.com.

Live coverage of each round, which begins at 1 p.m., can be found at USChessChamps.com.

Dennis J. McGrath • 612-673-4293