Many baseball scenes were clearly pieced together from different clips. Near the beginning, the Giants are at bat and the Braves are pitching, but the catcher is wearing a Colorado Rockies uniform. The Giants wear road uniforms at home numerous times. A few overhead shots show a football game at Candlestick Park. One scene shows fans in the seats at Candlestick Park, but the next shot is at Coors Field in Colorado.
When Rayburn collides with Primo, Rayburn's lucky #11 necklace breaks - both the pendant and the chain are shown on the grass. Later, when Rayburn goes to bat he feels for the lucky pendant - the pendant is missing but the chain is intact around his neck.
On opening day during the national anthems their is a over head shot of the stadium and it is clearly a 49er game you can see all the fans wearing red and the 49er flag waving at the top of the stadium.
The #11 patch on Rayburn's jersey is on the right sleeve as the jersey hangs in the locker, but the other players have it on their left. As the players are lined up during the pre-game ceremony, the #11 is no longer visible on Rayburn's right sleeve.
When Rayburn collides with Primo, Rayburn's lucky #11 necklace breaks -- both the pendant and the chain are shown on the grass. Later, when Rayburn goes to bat he feels for the lucky pendant -- the pendant is missing but the chain is intact around his neck.
Several times, the announcer says "Now batting, Bobby Rayburn", and Rayburn gets off the bench to approach home plate and begin the at-bat. In a real baseball game, he would come from the "On-Deck" circle as he was announced.
When Robert De Niro is counting his knives in his room, he picks one and throws it at the door, the blade penetrates to the outside. Right at this moment, a Hasidim Jew walks by the door holding a chihuahua dog. It is totally impossible for Hasidim Jews to own pets. Hassidisme is a very strict religious movement and owning pets is considered a purely secular/gentile hobby.
In the opening day game, the announcer says "Now leading off for the Giants, Lanz." He hits a foul ball, then Gil decides to go. Lanz swings at the next pitch and hits one deep to the outfield. Gil runs back to his son and asks him what he missed. His son says that he hit one deep and the bases are now loaded. This is again proved true when Rayburn hits a grand slam his at bat (he batted after Lanz). If Lanz was the first batter and got a hit, there would be only one man on base, not three, thus making a grand slam impossible.
When Gil opens his appointment book to see if he can do the meeting tomorrow, he turns to Friday where he drew "Opening Day". Even in the 1990's, opening day games always started either Sunday night or Monday.
In the film, when the Giants are at home at Candlestick Park, they are sitting in the third base dugout. In actuality, when the Giants played their home games at Candlestick, they sat in the first base dugout.
In the final sequence, Bobby Rayburn tries for an inside the park homer but is called out at the plate. Not only does he run the bases in a torrential downpour; it is pitch dark. At night games, stadium lights illuminate the field so it looks like daylight.
The goof item below may give away important plot points.
At the end of the film while Gil is dressed up as the umpire and the ball game is still in play, the cops are en route going to raid the the old ball park to find Bobby Rayburn's son. During this time the cops haven't yet made entry but are on there way meanwhile at the regular ball field Gil is found to be in the umpire suit and is shot, to which Bobby Rayburn kneels down and asks where his son is. Almost immediately after this the next scene is Bobby Rayburn going into the old ballpark with the police to get his son. The cops were already at the old ball field when Bobby and Gil were having there "showdown" at the ML ball field so therefore the police would have already had Rayburn's son out of there long before Bobby would have arrived, even via helicopter.