Baseball is America's national past time. It's played by both professional and amateur players during the spring, summer, and fall. Almost anyone of any size or ability can play baseball, which is why it's a very popular sport among children and adults.
Baseball is played on a field between two teams. Each team tries to score runs by hitting a baseball and advancing runners around four bases: first base, second base, third base, and home plate.
Each team has at least three opportunities within an inning to get players on base. If a player is unsuccessful as a batter or as a runner on base, he or she is out. Each team is allowed three outs per inning. After three outs, the teams switch positions. The team that was batting goes to the field to play defense, while the team that was on the field, gets its turn to bat and score runs.
There are nine players on each team: the pitcher, catcher, first baseman, second baseman, shortstop, and third baseman play in the infield, while the right fielder, center fielder, and left fielder play in the outfield. The infielders and outfielders try to prevent batters on the opposing team from scoring runs. (A "run" is a point, but don't use the word "point" in baseball!)
The main action takes place in the infield. A pitcher throws a ball to the catcher as the batter from the other team tries to hit the ball. A thrown ball is called a pitch. If a pitch is good, it can be counted as a strike if the batter doesn't hit it. If a pitch is bad, it's counted as a ball. Each batter is limited to three strikes and four balls. The umpire is similar to a referee. He makes decisions about whether or not a pitch is good.
Baseball is a little confusing until you know the rules and have watched a few games; however, if you are interested in American English, it's a good idea to learn a few things about how baseball is played.