Baseball is a bat-and-ball sport where two teams of nine players alternate between batting and fielding, with the offensive team aiming to score runs by hitting the ball and advancing counter-clockwise around four bases to touch home plate. The defensive team prevents runs by recording outs—through strikeouts, catching batted balls, or tagging runners—and a team's turn at bat ends after three outs, with games typically lasting nine innings (no game clock) and extra innings if tied, though modern pace-of-play rules like a pitch clock are now used. Evolving from English bat-and-ball games in the mid-18th century and developed in North America, baseball earned the nickname "America's Pastime" and became the unofficial national sport of the U.S., though it now trails American football in popularity. The sport spread globally, becoming especially popular in parts of Central and South America, the Caribbean, and East Asia, particularly in Japan, South Korea, and Taiwan. The highest professional level is Major League Baseball (MLB) in the U.S. and Canada, split into the National and American Leagues, with the champion decided by the World Series, while international competition features the World Baseball Classic and Olympic appearances from 1992 to 2008.