Billy Wagner is a former Major League Baseball pitcher who played for four different teams during his career. He was known for his powerful left arm and his ability to throw a fastball that could reach speeds of up to 100 miles per hour.

Wagner began his career with the Houston Astros in 1995 and quickly established himself as one of the top relievers in the league. He was named to the All-Star team four times during his tenure with the Astros and helped lead the team to the playoffs in 1997 and 1998.

In 2003, Wagner was traded to the Philadelphia Phillies, where he continued to excel as a closer. He recorded 21 saves in his first season with the team and was named to the All-Star team for the fifth time in his career. He also helped lead the Phillies to the playoffs in 2007, where they advanced to the National League Championship Series before losing to the eventual World Series champions, the Colorado Rockies.

After three seasons with the Phillies, Wagner was traded to the New York Mets in 2006. He continued to be a dominant closer for the Mets, recording 101 saves over three seasons with the team. He was also named to the All-Star team in 2006 and 2007.

Wagner's final season in the majors was in 2010, when he played for the Atlanta Braves. He recorded 37 saves that season and helped lead the team to the playoffs, but they were eliminated in the first round by the San Francisco Giants.

Throughout his career, Wagner was known for his fierce competitiveness and his ability to pitch in high-pressure situations. He finished his career with 422 saves, which ranks sixth on the all-time list. He also struck out 1,196 batters in just over 900 innings pitched.

Wagner was inducted into the Houston Astros Hall of Fame in 2019, and his number 13 was retired by the team. He was also named to the Philadelphia Phillies Wall of Fame in 2016.