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 Colorado Rockies are an American professional baseball team based in Denver, Colorado. The Rockies compete in Major League Baseball (MLB) as a member club of the National League (NL) West division. The team's home venue is Coors Field, located in the Lower Downtown area of Denver. The Rockies have won one National League championship, in 2007, after having won 21 of their final 22 games in order to secure a Wild Card position. In the World Series they were swept by the American League (AL) champion Boston Red Sox in four games. They are one of two MLB franchises to have never won a division title (the other team are the Rockies' expansion brethren, the Miami Marlins).