The Arizona Diamondbacks are a Major League Baseball team based in Phoenix, Arizona. The Diamondbacks are part of the National League and play in the West Division. Since beginning play in the 1998 season, the Diamondbacks called Chase Field (formerly named "Bank One Ballpark") their home. The name "Diamondbacks" was inspired by the Western diamondback snake and was chosen among thousands of entries in a contest to name the team.