Gaffes

Ishmael's chest tattoo is visible before he gets it.

Munsen's nose is bloody before Claudia hits him.

After Big Ern's first of three final strikes during the Reno Finals, Ishmael is visible sitting next to Roy, despite having just left with his brother.

When the band starts playing the national anthem, Roy is visible in the big-screen TV behind the stage, although he - in that moment - is supposed to be in the toilet vomiting.

Roy's hand holding the hook is visible after he flosses.

In the Reno tournament, Big Ern's foot crosses the foul line as he throws a strike. In tournament play, that would count as a zero and the pins would be reset.

Despite the popular urban legend, putting sugar into a gas tank will not ruin a car's engine (although it is very inconvenient). Sugar does not dissolve in gasoline, so although the crystals could potentially clog the fuel filters or injectors (requiring both them and the tank to be cleaned) it doesn't cause the massive damage that the legend suggests.

At the start of 10th frame of the final match, the announcer says that 3 strikes (30 points) would give Roy "a nice cushion". After Roy only earns 20 points, we are told he then has a 29 point lead over Ern, forcing Ern to score the maximum 30 points to win. Had Roy scored 30 points, he would have had a 39 point lead (more than Ern could possibly score). That's not a "nice cushion"; that's a victory.

When Claudia and Stanley doubled their money betting against Roy, they had to have bet on the winner Ernie. But Ernie's odds were 5:1, so they should have turned $42k into $210k instead of $84k.

The Amish wear subdued colors. All of the Amish depicted here are wearing bright blue, aqua marine, and purple shirts.

When Roy and Claudia are fighting in the parking lot, Roy goes to bite Claudia's ankle and his rubber hand actually "comes to life" and grips her leg.

When Claudia and Roy are fighting in the parking lot, you can clearly tell when Claudia's stunt double is being used. She looks much larger from the back and some of the edits are not very well done.

During the Reno tournament, there is a view of one of Roy's strikes from behind the pins. When the pins go down, the ball is still visible having stopped by the pins instead of continuing to roll off the end of the alley.

During the final match with Big Ern, Roy bowls both the 1st and final frame on the right lane. During tournament play, bowlers will alternate lanes each frame meaning he should finish the game on the opposite lane. (Also, they do show Roy bowling on the left lane during the match, meaning they must be following the alternating lane format).

During the Reno tournament, there are several instances where you can see the scoreboard above the lanes. Each time, the scoreboard has multiple names under each of the lane headings despite the fact that only one bowler is on each lane.

The Flag on the wall has the blue Union on the right, it should be on the left.

On a scene set in 1979, there's a guy drinking from a Coca-Cola bottle. However, it says "classic" under Coca-Cola. The word "classic" under Coca-Cola wasn't introduced until 1985.

In 1979, Roy uses a Brunswick Rhino bowling ball that wasn't introduced until 1987.

US Postal Service logo visible on mail box was not used in 1979.

In the scene from 1969, where young Roy leaps over a fence, a 1973 full-size Buick on cement blocks can be seen in the background in the garage next door.

When Roy is talking to Ishmael in the car, the camera is visible as a reflection in his sunglasses.

When Stanley discovers Munson has been gambling with a false wad of cash, he says "What's this? A hundred dollar bill wrapped in Monopoly money?" Actually he should have said: "Monopoly money wrapped in a hundred dollar bill?"