Richard Jessup’s brilliant 1963 novel was so short – barely 150 pages – it was almost custom-made for the movies. While it built up the tension to the confrontation between young stud poker contender The Cincinnati Kid (Steve McQueen in the film) and the reigning world champ Lancey Hodges (Edward G. Robinson) and covered the on-off relationship between the Kid and Christian (Tuesday Weld), a large chunk of the novel was in effect an insider’s guide to the world of poker and its unwritten rules.
As appeared always to be the case in translating novels to films, there were some incidental changes. The Kid was 26 in the book, but clearly in his 30s in the film. Lancey’s surname became Howard. In the book he was thin, in the film well-upholstered. Melba (Ann-Margret), the girlfriend of Shooter (Karl Malden) is not given a name in the book. The book is set in St Louis, the film in New Orleans.

But the book lacks sub-plots. It’s a straightforward narrative. The Kid decides to take on Lancey and while waiting for the game to be fixed up, having effectively broken up with Christian, he takes a 20-hour bus journey out to see her at her farm, returns on his own and for the rest of the book is involved in the poker duel with Lancey. Incidental characters make an appearance, Shooter as the dealer, some others including Pig (Jack Weston) making up the poker table.
The book doesn’t open with the Kid hustling, playing in a run-down part of town against inferior players, being accused of cheating, getting involved in a punch-up and being chased across a railroad yard. That’s all the invention of the scriptwriters Terry Southern (Barbarella, 1968) and Ring Lardner Jr. (Mash, 1970). The young shoeshine boy who interacts with the Kid several times throughout the movie doesn’t appear in the book either. And there was no cockfight in the book, that was also added by the screenwriters.
These were small devices to develop screen character. The punch-up showed that the Kid could take care of himself. The scenes with the shoeshine boy suggested that the Kid had begun early as a compulsive gambler, always measuring himself against an older player. And those scenes also demonstrated that gambling was not a sport for the kind-hearted. An actor with less confidence in his screen persona than McQueen might have insisted that he did not take the boy’s losing bet. (Such considerations are not rare – Robert Redford, for example, refused to play lawyer Frank Galvin in The Verdict unless the character was changed from being an alcoholic). The cockfight revealed that the characters mostly lived in an illegal world – the cops might turn a blind eye to a poker game in a private room in a hotel but would frown upon a bloody and brutal sport like cockfighting.
Sometimes, the screenwriters had to embellish certain scenes to bring them alive. The sequence where the Kid won over Christian’s parents with his card tricks is nothing more than a sentence in the book and characters like Pig are fleshed out.
But the most significant alterations to the book were the additions of two sub-plots. The first had Shooter, while acting as dealer, risk his reputation by agreeing to flip the Kid an occasional good card. This comes from being blackmailed by wealthy businessman Slade (Rip Torn) who threatens to call in Shooter’s marker, his gambling debt. Not only is this idea a screenwriter creation, but the character of Slade does not exist in the book. In fact, the whole idea runs against the unwritten code of honor among big-time poker players. And it would be extremely unlikely that Shooter would stoop so low. Even if broke, he would be able to eventually win back a stake. But if caught facilitating cheating his name would be mud and he would never play poker again in his life.

The second sub-plot concerns Melba (Ann-Margret). She exists on the periphery in the book. But she is something of a character, a genuine class act among the women who follow the game or are in relationships with the players. In the book, she was believed to have had a college education because “she read thick books and she dressed New York” and she attended arthouse cinemas. She was also admired for sticking with Shooter when his luck turned bad.
That’s not the character in the film. While not a gambler per se, she has a competitive streak and cheats at ordinary games – solitaire, jigsaw puzzles – where it makes no sense to cheat. In the book she is merely “beautiful;” in the film she turns into a man-eater, seducing the Kid, an action that went against her character in the book.
You would harldy argue that these sub-plots impaired enjoyment of the film. Perhaps those who read the book first might object. But, as ever, in examining what happens to books once they are bought up for the movies, each film examined is an example of the difference between a book and a film and how screenwriters compensate for perceived flaws. Some books, Blindfold, for example, required wholesale changes. Here, while the key storyline works like a charm, what was missing were the extra beats to ramp up the tension, otherwise there would be too long a wait in hanging around for the poker game to start. As a result of the sub-plots, what is put in jeopardy is the Kid’s relationship with Christian and his purity of involvement in the game itself, not just that any hint of cheating would bar him from the game, but that he wanted to beat Lancey fair and square so that, should he achieve that ambition, he would never have cause to doubt how he managed it.