But Marty’s greater happiness involves another secret, one that he’s scheming to spring on the world: that he, a Ping-Pong hustler who plays locally for modest stakes, is about to prove, in an international table-tennis tournament in London, that he’s the best in the world. For a scuffling guy from the Lower East Side, it’s a tall order; nonetheless, with his irrepressible energy and his wiles, he gets out of his low-rent neighborhood and into ever-wilder exploits that, in the story’s eight-month span, fling him about and leave him changed—perhaps even for the better.

Marty’s chutzpah is justified by history; the character is loosely based on the table-tennis hustler and champion Marty Reisman, who died in 2012, at the age of eighty-two. Like Marty, Reisman came from the Lower East Side and travelled overseas in 1952 for an international tournament. Other details, freely tweaked, mesh, too, but the main similarities are in temperament—a megawatt personality and a penchant for braggadocio.

Unlike Sandler’s gambler in “Uncut Gems,” Marty bets on no one but himself. It isn’t easy for Marty, who lives with his emotionally and financially dependent mother (Fran Drescher), to fund the trip to London: it takes ruses and threats and some outmaneuvering of his boss, his doting but tough uncle Murray (the writer Larry Sloman). So, once Marty gets there, he has to make the most of it. He finds the competition stiffer than he expected—especially from a Japanese player (the real-life table-tennis star Koto Kawaguchi), who uses a new kind of paddle and grip. But what matters even more than winning any one match is to get into the spotlight and into the higher echelons of society, since, to launch an international career, Marty needs rich backers—and, in any case, he craves fame and the trappings of success. Bulldozing his way into a suite at the Ritz, Marty focusses his impudent charm on a glamorous former movie star, Kay Stone (Gwyneth Paltrow), and also ingratiates himself with her husband, a wealthy businessman named Milton Rockwell (the entrepreneur, politician, and “Shark Tank” judge Kevin O’Leary) with an eye for publicity and, as he says, a nose for bullshit.

While there, Marty also partners with a Hungarian former champion, who survived Auschwitz (Géza Röhrig, who played an Auschwitz inmate in “Son of Saul”), in a table-tennis stunt duo. His relationship with Rachel, who works at a pet shop and has a lumpish husband, Ira (Emory Cohen), tightens—or, rather, she tightens it, with a ruse of her own. Then Marty faces a quandary, akin to the money emergency that screeches like a siren through “Uncut Gems”: hit with a fine by the table-tennis commissioner (the writer Pico Iyer) for boorish behavior in London, and left with little time to pay it off in order to enter a tournament in Tokyo, he starts Ping-Pong hustling again, in the company of a cabdriver friend named Wally (the rapper Tyler, the Creator). The result is a whirlwind of chaos that involves such out-of-control elements as a gangster (the filmmaker Abel Ferrara), a dog, a car crash, a break-in, a shoot-out, a fire, a flood, another affair, and a display of public defiance so brazen that it risks becoming an international incident.