21 is a perfect example of how something that's "based" on a true story can nevertheless exist mainly in the realm of fiction. While it's true that the source material for the movie, Ben Mezrich's Bringing Down the House relates events that actually happened, screenwriters Peter Steinfeld and Allan Loeb have fictionalized the entire story, leaving intact only the central idea that a group of MIT students devised a card-counting scheme that allowed them to fleece the Vegas casinos. And, while I'm firm believer in the adage "Never let the truth get in the way of a good story, " 21 doesn't spin a good enough yarn to justify all the changes. In fact, when one character indicates to another that he started out smart then got sloppy and stupid, he might have been referring to the script.
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