SUNNYVALE -- Solving a Rubik's Cube puzzle is relatively simple, insists Nathaniel Knopf. Anyone can do it with practice.

"It's really about recognizing patterns," said Knopf, 17, a junior at Tamalpais High School in Mill Valley. "Once you get over the initial hurdle of doing it once, people usually find it's pretty easy."

But not everyone can do it in less than 10 seconds, the way Knopf can. Or, like Riley Woo, whose best time is a shade more than 30 seconds ... while blindfolded.

"You're not really thinking of the cube in your head," said Woo, 16, a Burlingame High School junior. "You just do it."

Yeah, right -- piece of cake.

Remember, they're talking about the devilishly simple, yet wildly challenging game that was all the rage in the 1980s. Everyone understands the basic challenge: twist the cube containing mini-squares of six colors until each side of the cube is made up of the same color. And a majority of people who owned one likely never finished the fun-but-frustrating thing even once.

But about 100 "speedcubers" were easily solving puzzles Sunday in a friendly competition at the Moose Family Center Lodge in Sunnyvale, lining up the colors on the cubes in ridiculously quick fashion.

These cubists, ranging from age 8 to adults, came from as far away as San Luis Obispo, Seattle and Canada as a banquet-sized room was filled with the incessant clickety-clack sound of puzzles twisting. The only time you might see fingers moving this fast is when teenagers are texting their friends on smartphones.

What they made look effortless, of course, has driven mere mortals crazy. Brandon Harnish, 17, a Branham High senior, may have set a world record Sunday by taking only 2.19 seconds to solve a Skewb -- a variation of the Rubik's Cube -- in just nine moves, but his father doesn't have a clue how he does it.

"I don't get it in any way, shape or form," said Terry Harnish. "But I've found this is definitely a mathematical and engineering group. And most of them are musicians as well. It seems to require that kind of mindset. It's definitely a nerd-fest."

Cult following

The Rubik's Cube, in the parlance of enthusiasts, is a sequential movement puzzle. It was invented by a Hungarian named Erno Rubik, and reportedly more than 350 million have been sold, making it the world's best-selling puzzle.

While countless cubes may be collecting dust in abandoned toy boxes after its time as a must-have gadget long ago faded in this age of computer games, the Rubik's Cube has been enjoying a renaissance. The World Cube Association has about 30,000 members worldwide and tracks records in 18 events. (For instance, the current world mark in the standard Rubik's Cube is 5.55 seconds.)

"It died off in terms of being a trend in the public eye," Knopf noted, "but it always had a cult following, and now it's coming back."

Maybe more impressive than how fast Knopf and friends solve the cube is how six of them -- five in high school and one in junior college -- organized this event on their own. Competitors in nine events sat at tables outfitted with elaborate sensors and timing systems, which automatically started as soon as they picked up the cubes.

And the pressure was on because one entrant was Ron van Bruchem, 46, an Amsterdam resident who happened to be in Silicon Valley on a business trip. The Rubik Rock Star is a co-founder of the World Cube Association which has staged competitions around the globe.

"It's a big honor having him here," Brandon Harnish said. "But it's also nerve-racking."

"A few algorithms"

While this was van Bruchem's 105th event, he said the real competition is within yourself as you try to improve your time.

"When kids are just starting off and they think they're slow, I always tell them: 'It's OK, you're still better than 6 billion other people,'" he said.

Once featured in The New York Times, Woo specializes in the blindfolded competition. As soon as he picked up the cube, the clock started. After spending a few seconds studying the color pattern, he slipped down the blindfold and started twisting. His winning time was 46.63 seconds -- about 15 seconds slower than his best.

"You memorize a few algorithms beforehand, and when you're done, you hope it's solved, but you don't really know until you take off the blindfold," Woo said.

Richard Jay S. Apagar won the standard Rubik's Cube competition, the main event, by averaging 8.32 seconds in five times solving the puzzle. Brandon Harnish won the Skewb event with an average time 8.88 seconds. But while winners received gift certificates, Sunday was more about hanging out with others who share a Rubik's Cube fascination.

"Wherever I go," Brandon Harnish declares, " my Skewb goes."

On this day, he was surrounded by twisting people who feel the same way.

Follow Mark Emmons at Twitter.com/markedwinemmons.