Whether that figure is accurate or not, Cuba's iconic dictator provided an almost-mythical adversary for what became an obsessive, error-prone assassination campaign by the CIA.
The agency's attempts to kill Castro ranged from the calamitous to the comical. Many of them were detailed by the Church Committee, a special Senate subcommittee headed by Decomcratic Sen. Frank Church in 1975.
Giancana suggested that poison pills were more reliable than guns, so the CIA provided six pills of "high lethal content" to a cash-strapped Cuban official who had access to Castro, the subcommittee said.
However, after several unsuccessful attempts the Cuban got cold feet and the plan was abandoned.
Undeterred, the CIA tried an even more elaborate plan in 1963.
Intelligence officials thought they could use Castro's love of scuba-diving to topple him. They planned to hide explosives inside a large seashell and paint it with exotic colors to lure the attention of the ocean-loving communist.
Like many others, this idea was "discarded as impractical," according to the committee's report.
If many of these attempts have the air of a hammy "James Bond" film, Marita Lorenz was Castro's femme fatale.
Lorenz told Vanity Fair in 1993 that, while she was Castro's lover in late 1959, she was recruited as a contract-agent for the CIA and tasked with assassinating the Cuban leader.
She was given two botulism-toxin pills to drop in Castro’s drink, so her story goes. Just one would kill him in 30 seconds, but she got cold feet.
"I knew the minute I saw the outline of Havana I couldn’t do it," she told Vanity Fair, describing her emotions on landing in the Cuban capital.
Even if she had wanted to kill him, she had botched the job. She said she stashed the pills in a cold-cream jar that made them gunky and unusable. In any case, Castro had her rumbled.
"He leaned over, pulled out his .45, and handed it to me," she recounted. "He didn’t even flinch. And he said, 'You can’t kill me. Nobody can kill me.' And he kind of smiled and chewed on his cigar ... I felt deflated. He was so sure of me. He just grabbed me. We made love."
Her story isn't as ironclad as the details uncovered by the Church Committee. But given the CIA's track record it seems far from implausible.