He was the ultimate cold warrior, humbling the mighty Soviet chess establishment through his genius and a pounding ambition to be the best player in the world.
But Bobby Fischer's government believed he and his closest relatives might be Soviet spies.
FBI documents obtained by the Philadelphia Inquirer under the Freedom of Information Act show that intermittently, from the 1940s to the early 1970s, the Fischers were being watched. The FBI worried the Russians had tried to recruit the young chess prodigy during a trip to Moscow in 1958.
Agents also suspected his mother, Regina, might have been a Soviet operative. J. Edgar Hoover's agents interviewed informants, posed as student journalists, and considered cultivating other chess players. They hounded Fischer's mother, reading her mail, questioning her neighbors, studying her canceled checks.
It yielded little in the way of intelligence. The FBI concluded Regina Fischer was no spy, and that the Soviets had not tried to recruit her son.
Now 59, Bobby Fischer has become a reclusive, anti-Semitic expatriate. He has been seen in Japan, Hungary and the Philippines. In a Philippine radio interview on Sept. 11, 2001, he applauded the attacks and said America should be "wiped out."
Regina Fischer's 750-page FBI file is publicly available because she is deceased. A pediatrician, she died of cancer in 1997. The file touches only a sliver of her son's chess career _ a trip he took to Moscow in 1958, when he was the champion of U.S. chess at 15.
The FBI learned in 1957 that Regina had contacted the Soviet embassy to discuss the trip her son would take the following year for matches in the Soviet Union.
Before Bobby Fischer left for Russia in the summer of 1958, an agent posed as a college journalist to interview producers of the TV show I've Got a Secret. Bobby had been a guest on the show and won plane tickets to Russia. (Fischer's "secret?" He was U.S. chess champion. The panel was stumped.)
Despite playing well, Fischer was peeved at not being matched with the Soviets' best.
The FBI heard from another informant: Fischer had called his mother in the United States and told her, "It's no good here."
Agents weren't sure what to make of that. So they guessed.
"(I)t is possible that the Soviets may have made an approach to Robert Fischer to which the youth took exception," Hoover's office wrote to the New York field office in September 1958.
The next month, agents reported their finding: Fischer was a moody adolescent who didn't get along with his mother.
Who was Fischer's father?
Agents made it their business to find out. They checked his birth certificate; it listed his father as Gerhardt Fischer. He and Regina Wender had married in Moscow in 1933.
They divorced in 1945, two years after Bobby's birth, but the FBI believed they had been apart longer than that. Regina Fischer came here in 1939; the FBI said her husband never entered the United States.
The FBI seemed to pay more attention to Regina Fischer's Hungarian friend, Paul Nemenyi, who took a deep interest in Bobby Fischer. He paid child support and complained to social workers about the way Regina was raising the boy.
The censored files don't say if Nemenyi was Fischer's father. Letters obtained by the Philadelphia Inquirer offer an answer.
"I take it you know that Paul was Bobby Fischer's father," Peter Nemenyi wrote after his father's death in 1952. The papers also include a letter that year from Regina Fischer to Peter Nemenyi.
"Bobby . . . was sick 2 days with fever and sore throat and of course a doctor or medicine was out of the question," she wrote. "I don't think Paul would have wanted to leave Bobby this way and would ask you most urgently to let me know if Paul left anything for Bobby."
In the end, that's the picture the FBI was left with: nothing more than a worried single mother with a troubled son.