Baseball caps have developed along with baseball sports and are very, very popular in the United States. Most of the players who defend a team in the game are required to wear a baseball cap, so many fans will also wear their favorite hats. After it became popular, it was not just a baseball team's hat. Various styles and brands of baseball caps are very popular all over the world. Baseball caps have evolved along with baseball sports. Baseball sports are a ball game that features baseball playing as a main feature and is highly collective and antagonistic. It is widely carried out internationally and has a great influence, and is known as "combination of competition and wisdom".