Ten years ago, Charles Blahous (search) was a congressional staffer with a knack for numbers and a passion for baseball. He spent his free time tackling issues like the improbability of Joe DiMaggio's 56-game hitting streak.

These days, Blahous is more likely to be calculating the odds that President Bush will be able to restructure the Social Security system. If Bush succeeds, a share of the credit -- or blame -- surely will go to Blahous, the president's point man on the retirement program.

For more than a decade, Blahous has been neck-deep in the Social Security (search) debate, first on Capitol Hill, later as executive director of the president's bipartisan Commission to Strengthen Social Security, now as the president's special assistant on the issue. Along the way, he has developed a reputation as someone with the technical expertise, straight-shooting style and diplomatic skills necessary to shepherd strong-willed people toward common ground.

"He's down to earth," said Sam Beard, a Democrat who served on the presidential commission, "and I think the most important thing in this day and age in Washington is that he's totally willing to work in a bipartisan nature."

Blahous, 41, keeps a determinedly low profile in his work on the hottest domestic topic in Washington.

"I'm not really the public face of reform," he insisted to a reporter as he escaped up the steps to Air Force One (search) during one of the president's recent cross-country trips to promote private accounts carved out of Social Security.

Friends say Blahous is in his element now that Bush has put the issue front and center.

"It's a little bit like the dog that chased the bus and caught it," said Derrick Max, a good friend of Blahous and executive director of the Alliance for Worker Retirement Security (search), which represents business groups. "One side of Chuck is just as pleased as can be. It's his day." But, Max adds, there is some nervousness that comes with the responsibility.

Max says he met Blahous while presenting a paper on Social Security to an audience on Capitol Hill nearly a decade ago. Blahous raised his hand to point out that the numbers in one of the charts were wrong and then proceeded to recalculate the figures by hand.

"I don't want to call him the Rain Man, but that's sort of the image," said Max.

His outsized capacity with numbers is complemented by an ability to explain complex issues in understandable English. Take Blahous' conclusion to a statistics-packed Baseball Research Journal treatise he wrote on DiMaggio's hitting streak: "What all this means is that DiMaggio ... did something that he shouldn't have been expected to do unless he hit that way for 1,038 years."

White House spokesman Trent Duffy said Blahous is wearing out shoe leather shuttling between the White House and his office across the street in the Eisenhower Executive Office Building dozens of times a day. "He's constantly bringing back new charts, new data, new ways of looking at things," said Duffy.

Because Social Security is such a contentious issue, Blahous inevitably has his detractors.

"He has a long record of fighting to dismantle the guaranteed benefit Social Security's safety net provides," said Tony Chadhuri, a spokesman for the liberal advocacy group Campaign for America's Future (search).

Despite his consuming job, Blahous is engaged to be married and maintains an eclectic set of outside interests, including baseball, chess, classical piano and exotic travel. He and friends get together once or twice a month for Saturday "game days" where they can spend up to six hours playing board games such as Acquire, Mississippi Queen and Through the Desert that test mental strategy.

"It's like Monopoly to the 10th degree, or Clue to the 10th degree," explains James Hamilton, one of the weekend gamers. "Chuck usually wins."

While Blahous' strength undeniably is on the policy end of the Social Security debate, he also demonstrates keen awareness of its political overtones. His 2000 book on Social Security reform includes a chapter titled "The Top Ten Tricks in the Social Security Debate."

Peter Orszag, an economist at the Brookings Institution and former Clinton White House adviser, notes the Bush administration has been accused of using some of those tricks. But "among people who favor the type of reforms that he favors, Blahous is among the most honest and forthright," he said.

Despite Blahous' reputation for keeping his cool, he and Orszag did clash over a report in which Orszag questioned the findings of the presidential commission Blahous had directed.

Blahous fired back with a memo that Princeton economist Paul Krugman later wrote in The New York Times was "best described as hysterical. The number of non sequiturs and misrepresentations Mr. Blahous manages to squeeze into just a few pages may set a record."

Blahous keeps a framed copy of Krugman's article in his office.

Blahous, who has a doctorate in computational quantum chemistry (search), made the quantum leap to Social Security after coming to Washington as a Congressional Science Fellow working for Sen. Alan Simpson, R-Wyo. By the time Simpson retired in 1996, Blahous was his legislative director and was already seasoned in the Social Security battle.

"It's wonderful that the president is listening to him," said Simpson. "He wouldn't bend the reality or shave the reality to just get to a political result. He won't do that. Whether they may tire of that, I don't know, but they'll never have a more honest broker on a tough issue."