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)
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.
Factual error: The film takes place in the summer of 1962. The scene where the boys go to the local pool to swim, in actuality this is during the civil rights movement when racial injustice against African Americans was at its peak - they would have never allowed a young black child to swim in an all white pool during this year and time.
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.