Shoeless Joe Jackson's hat falls off when he hits a triple. After he makes it to 3rd base and stands back up, his hat is on.
Kenesaw M. Landis was elected baseball's first commissioner on November 12, 1920. The scene just after the announcement shows a newspaper dated January 14, 1920.
Ring Lardner unties his bow-tie on the train. Moments later, it's tied again.
In the final game of the Series, a Reds batter drives in several runners. The bat lies nearby in the dirt as Ray Schalk throws his glove down in disgust. In the next shot, a long distance shot from the stands, the bat is missing and Schalk's glove is back on his hand.
While playing for Hoboken, Joe Jackson's tobacco wad starts in his right cheek, while in the batters box and running the bases. When standing on 3rd base, waving to the crowd, the tobacco wad is now in his left cheek.
Shoeless Joe Jackson signs his confession with an X. Jackson was illiterate, but he could sign his name by mimicking a pattern. Autographed baseballs and photographs from the time prove it.
In the film, Risberg makes an error as shortstop in the first game. In real life, Chick Gandil made the only error.
Dickie Kerr, who pitched game 3 of the World Series, throws right-handed. In real life, he was a left-handed pitcher.
The ending implies that the "Black Sox's" banishment ended Chick Gandil's career. Gandil sat out the 1920 season because of a salary dispute with the White Sox.
In the film, Fred McMullin's role in the scandal is completely incorrect. McMullin overheard Chick and Swede's conversation in the locker room, not the bathroom, in August 1919. While McMullin was a friend of Swede's, he was only included out of fear he'd tell Gleason about the fix. McMullin earned his $5,000 by grounding out in game 2 with catcher Ray Schalk in scoring position. McMullin told Swede and Chick that he was going to tell the mafia that Swede and Chick were having second thoughts about throwing the series. From then on, McMullian served as an unofficial liaison for the mafia. The players were forced to throw several key games during the 1920 season out of fear of being exposed.
When the players meet their lawyers for the first time, the head counsel introduced his co-counsels by comparing them to famous ballplayers (i.e.: "The Ty Cobb of lawyers"). One player asks, "Who is the Babe Ruth?", and the head counsel replies "I am." In the time line of the film, between the 1919 and 1920 seasons, Babe Ruth would've just completed his final season with the Boston Red Sox. It was his first season playing more than 100 games, and he might not have been as famous as he became later. However, the players were indicted after the 1920 season. In 1920, Babe Ruth became the first player to hit 50 home runs in a season. He also set a hitting percentage record that stood for more than 80 years.
Cincinnati is the first team shown batting in Game 1, even though they are the home team. In the previous scene, when Rothstein first arrives to listen to the play-by-play, the announcer reads off the results of Chicago's turn at bat in the top of the first inning.
"The Star-Spangled Banner" wasn't officially America's national anthem until 1931. However, it was sung during the first game of the 1918 World Series, and had been popular for years. It could have been sung before a 1919 game.
Some neighborhood kids listen to the game on a "crystal set" radio. The first "real" radio station in the USA (KDKA, Pittsburgh, Pennsylvania) started in 1920, but smaller broadcasters were on the air as early as 1909. An enthusiastic local could have broadcast details of the game.
In one scene, a team photo is visible with circles around the players' faces. The grease pencil makes a grainy line, not a sold black line, revealing the photo as a high-resolution inkjet printout. Photos of the time would be finished by laying them on a sheet of glass coated in a thin layer of shellac, giving the photo a glossy look when the glass was peeled off.
The players' forefingers stick out of their gloves. That practice started in the 1950s.
In the room where live coverage of game one was being announced, after all the men leave, the announcer states the final score, calling Cincinnati's team the Red Legs. They weren't called the Red Legs until 1944.
Many newspaper headlines are in variations of the Helvetica typeface, designed in 1957.
Cominsky Park has a warning track. Warning tracks in ballparks first appeared after 1923, when the old Yankee Stadium was built with a running track for track and field events.
Early in the film, a close-up shows Eddie Cicotte's right hand as he prepares to throw his famous "shine ball." A "Rawlings" logo is clearly visible. In 1919, Major League Baseball exclusively used Spalding baseballs. They switched to Rawlings balls in 1977.
Dickie Kerr tells Kid Gleason that he remembers the first ball game he ever went to, where Gleason pitched a no-hitter to beat Cy Young 1-0. Kerr was born in July 1893. Gleason became a full-time infielder in 1895. He pitched for St. Louis, Kerr's home town, in 1892, 1893, and 1894. Kerr could have attended a game where Gleason pitched, but he probably wouldn't remember it. Plus, Kid Gleason never threw a no-hitter.
Catcher Ray Schalk wears his mask incorrectly; the gap in the mask for his eyes is at his forehead.