The Athletics (often referred to as the A's) are an American professional baseball team based in West Sacramento, California. The Athletics compete in Major League Baseball (MLB) as a member club of the American League (AL) West Division. The team will play its home games at Sutter Health Park in West Sacramento for the 2025–2027 seasons before its planned relocation to the Las Vegas metropolitan area. While in West Sacramento, the team is being referred to as simply the "Athletics" and "A's", with no city name attached. The franchise's nine World Series championships, fifteen pennants, and seventeen division titles are the second most in the AL after the New York Yankees. One of the AL's eight charter franchises, the team was founded in Philadelphia in 1901 as the Philadelphia Athletics. They won three World Series championships in 1910, 1911, and 1913, and back-to-back titles in 1929 and 1930. The team's owner and manager for its first 50 years was Connie Mack, and Hall of Fame players included Chief Bender, Frank "Home Run" Baker, Jimmie Foxx, and Lefty Grove. The team left Philadelphia for Kansas City, Missouri, in 1955 and became the Kansas City Athletics, before moving to Oakland, California, in 1968 and becoming the Oakland Athletics. The Athletics played their home games at the Oakland Coliseum from 1968 until 2024. Nicknamed the "Swingin' A's", under owner Charlie O. Finley they won three consecutive World Series in 1972, 1973, and 1974, led by players including Vida Blue, Catfish Hunter, Reggie Jackson, and Rollie Fingers. After being sold by Finley to Walter A. Haas Jr., the team won three consecutive pennants and the 1989 World Series behind the "Bash Brothers", Jose Canseco and Mark McGwire, as well as Hall of Famers Dennis Eckersley, Rickey Henderson and manager Tony La Russa. In 2002, the Athletics set a then American League record for most consecutive wins in a season with twenty, an event that would go on to be the pioneering step in the application of sabermetrics in baseball. The streak record was later broken in 2017 by the Cleveland Indians. From 1901 through the end of 2024, the franchise's overall win–loss record is 9,329–9,859–87 (.486).

Sutter Health Park

The Boston Red Sox are an American professional baseball team based in Boston, Massachusetts, that competes in Major League Baseball (MLB). They are members of the East Division of the American League (AL). The Red Sox have won 8 World Series, having appeared in 12. Founded in 1901 as one of the American League's eight charter franchises, the Red Sox's home ballpark has been Fenway Park since 1912. The "Red Sox" name was chosen by the team owner, John I. Taylor, around 1908, following the lead of previous teams that had been known as the "Boston Red Stockings", including the forerunner of the Atlanta Braves. Boston was a dominant team in the new league, defeating the Pittsburgh Pirates in the first World Series in 1903 and winning four more championships by 1918. However, they then went into one of the longest championship droughts in baseball history, called by some the "Curse of the Bambino" after its alleged beginning with the Red Sox's sale of Babe Ruth to the rival New York Yankees two years after their world championship in 1918, an 86-year wait before the team's sixth World Championship in 2004. The team's history during that period was punctuated with some of the most memorable moments in World Series history, including Enos Slaughter's "mad dash" in 1946, the "Impossible Dream" of 1967, Carlton Fisk's home run in 1975, and Bill Buckner's error in 1986. Following their victory in the 2013 World Series, they became the first team to win three World Series trophies in the 21st century, including championships in 2004 and 2007. Red Sox history has also been marked by the team's intense rivalry with the Yankees, arguably the fiercest and most historic in North American professional sports. The Boston Red Sox are owned by Fenway Sports Group, which also own Liverpool F.C. of the Premier League in England. The Red Sox are consistently one of the top MLB teams in average road attendance, while the small capacity of Fenway Park prevents them from leading in overall attendance. From May 15, 2003 to April 10, 2013, the Red Sox sold out every home game—a total of 820 games (794 regular season) for a major professional sports record.