Officials of The Philadelphia Inquirer National Sudoku Championship have disqualified the third-place winner of the Oct. 24 tourney after an investigation, which included a retesting at The Inquirer last week.

Eugene Varshavsky of Lawrenceville, N.J., was stripped of his $3,000 prize after doing poorly in the retest. The money now goes to Chris Narrikkattu of New York City, who placed behind Varshavsky in an intermediate round. Varshavsky could not be reached for comment.

In a statement yesterday, tournament director Will Shortz, "Puzzlemaster" of NPR's Weekend Edition, said that "when we observed the inconsistent results in the advanced finals, we commenced an investigation."

On Oct. 24, Varshavsky made the final three contestants out of 646. He qualified for the finals by blazing through three puzzles in a world-class time of 14 minutes.

In the finals, Tammy MacLeod of Los Angeles won the first prize of $10,000. Former world champion Thomas Snyder won the $4,000 second prize, but not without some drama. Snyder turned his entry in early, believing he had won, but he soon saw he'd made a mistake and could do no better than second.

Varshavsky then had 20 minutes, a great deal of time in such competitions, to complete the puzzle and possibly take second. But he could fill in only three digits of the final puzzle after eight minutes. Even in very hard Sudoku puzzles, initial boxes are relatively easy to fill in. His poor performance still assured him third place and the $3,000.

Narrikkattu, speaking by phone from the Bronx, said, "I have to say that after the qualifying rounds, I was befuddled, wondering who this guy was. I don't know too many people in the Sudoku community who are that fast. And then, at the finals, you had Tammy working like crazy, Thomas working like crazy, and Eugene just standing there. I had an inkling something was wrong, but couldn't figure out how you could cheat in a Sudoku tournament with all the people around."

Narrikkattu said that reports of Varshavsky's irregular behavior at the 2006 World Chess Open cemented his suspicions.

Spurred in part by protests in the blogosphere, including Snyder's much-read blog, "The Art of Puzzles," Shortz and Nick Baxter, director of judging, decided to conduct an investigation. Prize money at the advanced level was frozen, and the investigation soon focused on Varshavsky, whose hooded sweatshirt covered his head in the earlier rounds.

He was asked last week to come to The Inquirer and complete further puzzles to establish his skill level. He did not do well enough to persuade the directors, and was disqualified.

"The reexamination results were very much consistent with Mr. Varshavsky's onstage performance," Shortz said in the statement. "We have concluded that Eugene Varshavsky alone could not have solved the Round Three puzzles during the championship and, therefore, based on the rules of the championship, which prohibit 'outside help' and grant [judges] the right to disqualify, have decided to disqualify him from his third-place Advanced Division prize."

Varshavsky originally was asked to take the retest Wednesday, but kept rescheduling for later and later in the day, so late the retest had to be held over until 9:30 a.m. Thursday. Baxter, who had flown in from San Francisco, administered the puzzles; Shortz had to return to New York, but a video of the retest results was e-mailed to him. He consulted with Baxter and Carol Dooling, marketing and communications director of Philadelphia Media Holdings L.L.C., which owns The Inquirer, in deciding to disqualify Varshavsky.

Baxter followed a simple method in the retest.

"I started out with the most fundamental: Let's give him one of the same puzzles he solved in Round Three," Baxter said from Hillsborough, Calif. That was the round in which Varshavsky showed such speed and skill. But he filled only nine of the 81 digits in 15 minutes.

He was then given another puzzle he had solved in the tournament, and after more than eight minutes he could fill in only two digits correctly. Then he was given two puzzles from an earlier round and could do neither.

"Eugene did recognize what was going on by the second puzzle," Baxter said. "What he did in the reexamination is pretty much what he exhibited onstage, and pretty much confirms the gross disparity that was observed in the championship, and we really had no alternative, no other explanation, and he offered no other explanation."

Baxter said that although the conclusion was obvious, there was no direct evidence of cheating. "He must have had some help in Round Three," he said. "There are some high-tech explanations, some very low-tech. It really doesn't matter how he did it."

Varshavsky was notified of the results yesterday morning and requested a retest, but tournament officials told him that a sufficiently fair process had taken place and declined. He could not be reached for comment.

"He had excuses," Shortz said. "He said his earphones were tight, and that distracted him, and he said he was tired. But to all of us, the disparities were so stark that tiredness could not have accounted for his poor performance in the retest."

Narrikkattu said he was "ecstatic" to have placed third, and called the whole story "pretty wild."

Some competitors, including second-place winner Snyder, have called for rule changes that would ban electronic devices. Shortz said that although nothing had been decided yet, it is likely some rules would be added or changed for next year's national championship.

The Inquirer will host the 2010 World Sudoku championships here in April.

"Speculating now," said Shortz, "I think we will forbid any electronic devices on desks. This year, we did permit iPods, and almost certainly we will forbid those next year.

"A second big thing is that any contestant will be subject to search. We've never had to search anybody before." He agreed that the need even to consider such changes was sad.