The Lone Star Series (also known as the Silver Boot Series) is a Major League Baseball (MLB) rivalry featuring Texas' two major league franchises, the Houston Astros and Texas Rangers. It is an outgrowth of the "natural rivalry" established by MLB as part of interleague play as the Rangers are a member of the American League (AL) and the Astros were a member of the National League (NL) until 2012. During interleague play, the winner of the six game series was awarded the Silver Boot, a 30-inch (760 mm) tall display of a size 15 cowboy boot cast in silver, complete with a custom, handmade spur. If the series was split (3–3), the winner was the club which scored the most runs over the course of the series. In 2013, the Astros joined the American League West with the Rangers and changed their