In real life the team's success was 90% in being careful to not attract the attention of the casinos detectors and only 10% in their scheme, which was based on the well-known technique of card-counting to get an edge. In the movie, the team's actions were childishly crude even to the point of continually returning to the same casino...so the movie makers could develop the characters of the casino bad guys. In real life the team was careful to not win much at any one table or at any one casino, not more than $1,000 a session, which would be well within the amount any lucky player might win without counting. In the movie they hit the same table for tens of thousands of dollars, which would have set off alarms all over Nevada. Even the hand signals the team used in the movie were childishly obvious. All this by the supposedly brilliant MIT students and professor. No way.
The movie actually had the bad casino guys torturing card counters when they caught them. No way. In real life a casino has the right, tested in court, to kick anyone out and ban them from ever playing again...they do not have to prove cheating or card-counting, they do it under the laws of trespassing on their private property and this is what they do. Remember, card-counters are only making what amounts to an hourly wage, so they are not a serious threat to a casino.
Another example of the Hollywood treatment was that after showing how brilliant Ben was at counting cards when they were recruiting him, he was not used as the card counter, he was used as the big bettor and one of the female team members did the counting.
an entertaining movie for someone not knowledgeable or much interested in real life casino gambling, but dumb and dumber for those who are.