Things significantly different in the book than in the movie:
There were two that I found very significant.
In the movie, during the Paris tournament, Beth goes on a drinking and sex binge and ends up playing less than perfect against Borgov, and losing. The whole drinking and sex binge was totally absent from the book. She played Borgov, and lost. In the book, her conflict with Borgov was part of displaying her addiction. After the Paris tournament, she ends up going into her real binge drinking, ignoring chess for a while. In the book, Jolene helps her out of it, but she is the one who initiated the conflict.
The other scene that I found significantly different, although it was a very small thing, was the final scene. In the movie, she was on her way to the airport with her State Department handler, and she defiantly leaves the car and goes to find the old men playing chess in the park. The book ended in the same park, and with the same line of dialog, but it was simply what she did at the end of the tournament, the day before returning home. There was no hint of rebellion or of defying the State Department guy. It was just a case of, after winning a prestigious tournament, and beating the man that had been her nemesis for years, what did she do? She played Chess.
There were a few other things that they changed for the movie, but I don't think they were incredibly important. They just seemed to add some drama. It didn't really advance the plot, or the theme, of the book, but it created dramatic moments that weren't in the book.
After watching the movie, there were some things in the film that I didn't think were wrapped up very well. There were things I wondered about. I liked the movie well enough to decide to read the book. This is a sort of review for anyone who might be tempted to do the same.
First, there were some significant differences between the book and the movie. The plot was very recognizable and hit the same important points, but there were some side scenes that were substantially different. I won't describe them in this post, but I will write a subsequent post talking about them, so if you are tempted to read the book, but don't want to hear about what happens until you read it, don't go on in the thread. You have been warned.
One thing I really liked about the book was that his writing really captured the emotional feel of the chess games even better than the movie did. He would describe the moves on the board, but more often he would describe the thought processes, including the emotional state of Beth Harmon as she played. Some of the games were boring. In some she practically held her opponent in contempt. In the losing games she felt strangled and helpless. In challenging games the author did a good job of capturing that feeling of anxiety knowing that there must be a way to win this game, and a feeling of triumph if it is found, or desperation if it is not.
Another thing I think the book did better than the movie was in covering the general theme of addiction. The movie had a sense of Beth fighting addiction, and when she was able to break free of the alcoholism or drug dependency, she would triumph on the chess board. In the book, it is a little bit more obvious that the choice between chess and booze was not the choice between addiction or non-addiction, it was a case of choosing which addiction to follow. The chess addiction was not nearly so destructive as alcoholism, but it was still an addiction.
In general, I would say that if you liked the film, you probably would like the book, and they were mostly similar. The significant departures from the book were ones that often created more of an emotional hook, but the basic story is not altered. However, the book only adds a little bit to what the movie said. Most, but not all, of the emotion in the book came through in the movie, so there is not major revelations within the book that explain the loose ends in the movie.
Overall, I can recommend it, but not enthusiastically. This is one case where seeing the movie is almost as good as reading the book. In some ways, one or the other is maybe a little bit better.