A lot of Marty Supreme is rooted in real people and history, but the movie itself is a heavily fictionalized story rather than a straight true account. The main character, Marty Mauser, is loosely inspired by real-life table tennis hustler Marty Reisman, whose memoir and larger‑than‑life persona gave the filmmakers much of the tone, subculture, and hustler vibe, but not most of the specific plot events.

What’s basically true

  • Marty as a table‑tennis hustler: The idea of a fast‑talking New York ping‑pong prodigy who gambles, hustles rich opponents, and lives on the edge comes straight from Marty Reisman’s real reputation as a “bad boy of table tennis” and legendary gambler.
  • The 1950s–60s ping‑pong scene: The smoky clubs, backroom money games, and oddball New York characters around table tennis are drawn from real places and people Reisman played with, like midtown clubs and private parlors full of misfits and high‑rollers.
  • The mix of sport and con‑artist life: Reisman really did blend high‑level competition with hustling, traveling, and pulling schemes to keep himself afloat, which the film exaggerates but doesn’t invent from nothing.

What’s mostly fictional

  • The exact plot line: The film’s detailed story beats (robberies, affairs, specific matches, business pitches, and who wins what tournament when) are constructed drama, not a factual retelling of Reisman’s career.
  • Side characters and relationships: Many of the major supporting figures (romantic partners, business moguls, specific friends and rivals) are composites or inventions that echo real types of people around Reisman, rather than identifiable real individuals.
  • Big dramatic set‑pieces: The movie’s most perfectly structured, high‑stakes sequences are shaped for cinematic tension; they may be loosely inspired by anecdotes or legends from the scene, but they are not documented events you could line up with historical records.

So, how much of it is “true”?

  • The spirit and world (time period, subculture, tone, and the idea of a notorious ping‑pong hustler) track closely with reality.
  • The specific story you see on screen is best understood as historical fiction: it borrows a real person’s legend and environment, then builds an original, heightened narrative on top.

In other words, it’s not “a true story,” but it is loosely based on a very real figure and a real hustler subculture that were already wild enough to inspire the film.