Revealing mistake: When the boys' rival team challenges them, all the boys throw their gloves down, except Yeah-Yeah. When they all go to pick them back up, Yeah-Yeah has to pretend to pick it up.
Continuity mistake: When Smalls tries to throw the ball for the first time, everyone laughs at him and falls down. When it shows the guys from Smalls' view, it shows Yeah-Yeah falling down. Then when Smalls is running away, it shows Yeah-Yeah falling again.
Continuity mistake: When the fence is about to fall on the dog, it changes camera angles. In each camera angle the fence falls in different directions. Plus when it starts falling, the dog turns around facing the fence, but when it falls on him, he is facing the other way.
Factual error: Although the movie is set in 1962, when Rodriguez jumps the fence of the junkyard, a red door from a '73-88 GM pickup can be seen in the background.
Factual error: At the beginning of the carnival scene, the Gravitron ride is in the far background. This movie is set in 1962, and the Gravitron was not introduced until 1983.
Factual error: In his voiceover narration, Smalls says that Babe Ruth's "called shot" was made at Yankee Stadium in the bottom of the ninth inning in game 3 of the 1932 World Series. That play actually occurred in the top of the fifth inning at Wrigley Field. It's not just a character mistake; the event is too famous for him not to have heard or read about it growing up, especially since his stepfather is a Yankees fan.
Continuity mistake: At the end when Benny gets the ball and runs from the beast he hops the fence. The ball is in his right hand as he jumps. When the gang helps him up, he doesn't have the baseball in his right hand. As he's running through town the ball is back in his right hand.
Continuity mistake: When the vacuums explode in the clubhouse, Benny jumps over the railing right after Bertram and you see him fall past Ham. Almost 10 seconds later, Ham drops off the ladder. The next shot shows Ham and Benny hitting the ground at the same time.
Revealing mistake: When the kids are at the pool and Squints has just jumped in the deep end, the other kids go crazy and then you can see water on the camera.
Revealing mistake: When the Babe Ruth ball is thrown to Smalls, smoke from a ball launcher is visible before Smalls hits it.
Continuity mistake: A while into the chase scene at the end of the movie, the dog chases Benny through the founders' celebration. A large cake, about four or five tiers high, is being carried by a couple of bakers. They lose their balance and set the cake down, but eventually it gets sent into the air. While going up, it stays whole, but the shot changes when it's coming down, and it has now broken apart into many small pieces.
Continuity mistake: During one attempt to retrieve the ball, the boys use a pot attached to a long piece of angle iron. When they flip the whole contraption over to grab the ball, the part of angle iron outside the fence is still facing in the original direction.
Continuity mistake: In the shot that Squints exits the pool, he is not wearing his glasses. In the next shot of his face, he is wearing his glasses. This all happens in back-to-back shots, all within the pool area. (00:37:35)
Continuity mistake: After Squints kisses Wendy and the boys leave the pool area, Ham asks Squints if he planned it, and he looks back at Wendy. When the shot changes, some of the boys change position. For instance, Timmy is standing before the shot change, but sitting immediately afterward. (00:40:55)
Continuity mistake: When Benny knocks the cover off the baseball, the boys gather around the cover on the ground and marvel at the accomplishment. The position of the cover changes from shot to shot. When they first show the cover, it is lying flat with the ends sticking up. They then show the boys. They then show the cover, and one half is now resting on its side and more detached from the other half. No one ever reaches down to touch the cover. (00:46:45 - 00:47:45)
Factual error: At the last shot of the Fourth of July game of the Sandlot, high-pressure sodium area lights can be seen in the distance on the right side of the screen. This type of lamp was not developed until 1964 (two years after when this movie is set). (00:44:06)
Continuity mistake: When Wendy is performing CPR on squints the people watching it change positions throughout of the scene.
Audio problem: When Benny and the others are looking at the destroyed baseball, when Benny and Kenny are talking their mouths are out of sync with what they are saying.
Continuity mistake: When the gang are at the pool the sky changes between shots from a cloudy day to a sunny day, especially when they're kicked out of the pool.
Continuity mistake: When Squints yells "no!" and the gang run towards the fence to stop Smalls, Yeah-Yeah's hat appears and disappears between shots.
Answer: It's a blue hat with a yellow/gold capitol "C" for the logo, which doesn't correspond to any major league teams. It could be a minor league or school team hat. Benny refers to it as his "old" hat, so he may have replaced it with the Dodgers hat he's wearing.