When KGB and Mike are playing heads up in the end of the film and Mike is dealing the cards he first deals the "turn card" i.e. the fourth community card and then deals the "river", fifth community card, without discarding one card. In Texas Hold 'em you always take the top card away when dealing the community cards because cards can be marked and by doing so no-one will know which cards are coming even if some of them are marked. [That is not correct. You only see them play four hands in total, the rest are just implied by their stacks changing size, and only once is Mike shown to be dealing. When he does, the camera comes on him just as he deals the turn card (so you can not tell if he discarded one before this), and a little while later you can see him discard one card before dealing the river.]

In the final showdown with Mike & KGB, Mike goes to the poker showdown with $10,000. In the first game, he beats KGB in a winner take all and doubles up. If that is the case, Mike would now have $20,000. Mike gets ready to leave, but KGB goads him into playing another game for double or nothing. Mike again beats KGB to double up to $40,000. However, Mike states his winnings to be $60,000 with the breakdown of his winnings as follows: $15,000 back to KGB and Gramma, $10,000 back to the law professor and $6,000 back to the Chesterfield. This totals $31,000 which would leave only $9,000 left. Where did the other $20,000 come from? This amount is never accounted for in the movie in the final showdown with KGB. [It was not mentioned how much KGB started the second game with, it could have been 40,000. Most likely though, KGB started with 20,000 and lost it, then brought another 20,000 into the game. Remember Mike said KGB could "reload at anytime".]

When Mike is playing KGB for the second time, right before he throws his Oreos they are almost gone but in the next shot it is almost a half full again. [The Oreos don't change.]

There are several instances of improper poker playing in this movie. 1. When KGB is going to bet 15,000 into Mike early on, he puts one stack of chips out, then reaches for more and announces his bet. This is called a string bet, going back for more without FIRST announcing how much you are putting in. KGB's bet should have only been his first stack. 2. In one of the home games while Mike is trying to win back money, a man says, "I call your 1,500, and bet all-in" or something. He should have said, "I see your 1,500..." By saying "call" he is calling, and therefore can't put any more money in the pot. 3. There are several players who "splash the pot." Putting chips right into the middle, instead of a little in front of you until the betting round is over. [Mike tells KGB to stop splashing the pot, and Teddy says that in his club he will splash the pot if he wants to. Not really a trivia, since they acknowledge it.]

In the final card hand between Teddy KGB and Mike, Teddy lays down an ace and goes "all in," commenting menacingly to Mike that "Your fate is sitting right beside you," implying that loan shark Grama is waiting to break a few bones once Mike cannot pay off the debt he inherited from Worm. But if you look at the table, Mike has at least three times the number of chips that Teddy has, even more than when Mike won the $10,000 from Teddy earlier. Mike does not have to go "all in" (which he does), but merely call the bet. Even if he were to lose that hand, he would still have more chips than Teddy, enough to pay Grama off. You would think Teddy would know that, since the chips are right there on the table. His comment that Mike will not be able to pay Grama doesn't make any sense, although it does heighten the drama. [Even if this was a mistake, it's a character mistake on Teddy's part. Whether or not he realised that he had more is not a movie mistake. Besides, what Teddy was doing was more likely deliberate to try to put Mike off. Teddy knew that he had beaten Mike before, and it came from Mike being too overconfident and not betting wisely. If Mike bet large and lost, Teddy would probably get all his money back instead of losing a large amount of it.]

During the part where Matt (Mike) is on the bed he tosses his hat on it, but in the next shot the hat is gone. [Mike takes off his coat, and while the camera is focused on his girlfriend, he knocks the hat on the floor.]

When Mike is playing KGB at the end of the movie, in the last hand of the first game they play when Mike wins with Jacks Up, Mike is the dealer. However when Mike reaches out to rake the chips in, the deck of cards is sitting in front of KGB, to the right of where his chips were. [They played with two decks it seems.]

After Mike is taken for every penny, Judge Petrovisky writes him a personal check for $10,000, which he then takes to a check cashier. These businesses take between 2.5 to 5 percent for cashing a personal check, yet he is able to show up at KGB's club with the full ten thousand. [This is not a mistake, had the movie been watched and subsequently examined closely one would have heard that after Worm and Mike were beaten up at the lodge by the state troopers, Mike tells Worm he has $350 in his shoe, which in turn accounts for the 2-2.5 percent acquisition fee from the cashier station.]