While sudoku's popularity may have dimmed, it would be foolish to dismiss it as a short-lived fad. A 5-year-old boy with a snowflake design on his shirt stares at a white sheet of paper, his eyes parachuting down on a 9-by-9 grid.

Some squares inside that grid contain numbers. Some don't.
Jason Gu, the son of two Chinese immigrants, studies his sudoku board. He sits at the same table as a 91-year-old woman from Emerson, a 16-year-old high school student from Ringwood and his 10-year-old sister Janice.

Nine others are on the same side of the table, up on a dais inside the Mahwah Room at the Sheraton Crossroads. Quiet descends as 13 players race to squeeze the numbers 1 through 9 into rows, columns and boxes. No number can appear more than once in an individual row, column or box.
"Time's up," says Reenaa Chawla, the tournament director. "Please put your name on your sheets."

Two years after it began flourishing in newsprint, throwing a scare into its older sibling (the crossword puzzle), sudoku has fallen back to earth. Some say its best days have passed.
"I don't expect it's going to return to its former self in the near future," said Walter Boyer, owner of Bookends, an independent bookstore in Ridgewood.

Others suggest while its popularity may have dimmed, it would be foolish to dismiss it as a fad that swept through the United States one summer. This month, Dell is launching a bimonthly puzzle magazine called Sum-Doku. The first issue, due to hit newsstands this week, will include 176 puzzles that are hybrids of the conventional sudoku puzzle.

"I think it will be with us [for a while]," said Will Shortz, the crossword editor at the New York Times and author of dozens of puzzle books, including several sudoku titles.
Chawla has 13 people gathered at a hotel on this Wednesday night -- five young kids, one teenager and seven adults. Chawla, the head of the Brain Studio in Mahwah, is a proponent of something she calls "brain fitness." She loves sudoku because it offers the intellectual equivalent of taking the brain out for a jog.

"Twenty years back it would be crazy to suggest, 'Take the steps instead of the elevator, and it will do good for your heart,' " Chawla said. "But now it's an accepted norm today."
And Chawla has an interesting assemblage here this evening, including 91-year-old Astrid Sverdrup.

"She used to bowl years ago, so she used to add [up] everybody's score," said Joanne Burns, Sverdrup's daughter. "She has an affinity with numbers."

Sverdrup learned how to play by watching her niece. Janice and Jason Gu learned after their father, Eddie, happened upon the game in a magazine.

"We're immigrants," Eddie Gu said. "[With] crossword puzzles, there's a lot of words we just don't know. But this, you don't really need to know a lot of the cultural stuff."
Yet already people are stepping back, buying fewer sudoku books, filling out fewer sudoku grids.

Boyer said his Ridgewood store sells a lot of sudoku books around the holidays, but in general, sales are down.
"It's oversaturated, I would probably say at this point," Boyer said. "We're waiting for the next type of game."
But Shortz said sudoku is safely ensconced as the next great pencil-and-paper puzzle. He likens sudoku's rise two years ago to the explosion of crosswords in the 1920s.

"The country just went crazy," Shortz said. "A lot of people thought crosswords would be like other fads of the country. That was not the case. Crosswords had staying appeal."
Even as sudoku's popularity wanes, 13 men, women and children are sitting inside a conference room in Mahwah, scrambling for the numbers that will make their puzzles and lives more complete.