For those who want to know what really went wrong with the most famous bad boy in chess, there’s Bobby Fischer Against the World. It’s the latest from Liz Garbus, the maker of many thoughtfully confrontational documentaries about class conflict and systemic injustice, including Ghosts of Abu Ghraib and The Fence, about the U.S.-Mexico border.

“Chess is a game of war,” the filmmaker says, in Toronto for her film’s debut at the Hot Docs festival. “And Bobby Fischer John Wayned it better than anyone else. But he was also funny and had a kind of charming, charismatic side that has been forgotten.”

Fischer’s whole persona, in fact, was eventually engulfed by his paranoid delusions. The documentary, which opens here Friday (July 22), puts his eventual meltdown in a Cold War context, culminating with his 1972 Icelandic face-off against Russian master Boris Spassky. Fischer’s spectacular board baron, who ended life as a bushy-bearded prophet of crazy, would have been odd in any era.

“People who knew Bobby say he had Asperger’s syndrome or borderline personality disorder. He certainly had some untreated mental issues that probably contributed to his death. But his socialization by chess certainly had a lot to do with his awkward personality. At the same time, with Dick Cavett and certain interviewers he connected with, he could be rather open and charming—but still quite arrogant, of course.”

For a fellow who loudly opposed having his picture taken, he had a close friendship with Scottish photographer Harry Benson, who made those great shots of the Beatles meeting Muhammad Ali.

“Harry penetrated Bobby’s inner sphere in those crucial years. I can tell you that Harry’s a very pleasant person to have around, and he was somehow able to worm his way in there. Without his incredible black-and-white photos, I wouldn’t have been able to make this film.”

Benson was spared the lethal contradictions that otherwise ruined Fischer’s connections with people—especially later, as an American Jew who morphed into an anti-Semitic Yankee basher.

“All of Bobby’s passions and prejudices were things he picked up from his parents”¦You know, his mother, who was a big antinuclear activist, hid her Judaism when she was young, and there was certain confusion there. He was also a born provocateur, and what better way to do that than to reject everything around you? He was like the child at the table who says his first swear word and gets a big reaction. Only he never stopped.”

The filmmaker’s own father, Martin Garbus, is a top first-amendment lawyer who defended caustic comic Lenny Bruce and was featured prominently in his daughter’s Shouting Fire: Stories From the Edge of Free Speech. This surely fed her fascination with the marginalized, the forgotten, and the misunderstood.

“I was inspired to do this story the day I read Bobby’s obituary,” she recalls. “I wanted to reconstruct the summer of 1972, when the whole world was chess-obsessed and the geopolitical order hinged on two guys sitting at a table in Reykjavik.”

Watch the trailer for Bobby Fischer Against the World.