After high school Blum attended the University of California, Berkeley. On June 2, 1994 he was drafted by the Montreal Expos (Now Washington Nationals). After playing in the minor leagues for a few seasons, he was called up to make his MLB debut on August 9, 1999. In 2000 he earned a full roster spot with Montreal, playing in 124 games in 2000 and 148 games in 2001.

On March 12, 2002 the Expos traded Blum to the Houston Astros. He again joined the Astros roster, averaging 125 games each season. After two seasons with the Astros, he was again traded to the Tampa Bay Devil Rays on December 14, 2003. In the middle of the 2004 season Blum was released by the Devil Rays and signed as a free agent San Diego Padres on December 9, 2004. Just a few months later Blum was traded again this time to the Chicago White Sox on July 31, 2005. With the White Sox, Blum made his first post season appearance and played in the 2005 World Series. He hit a homerun to win game three of the series, which the White Sox ended up winning against the Houston Texans.

Blum signed as a free agent back with the San Diego Padres on November 16, 2005. The following year he joined the Padres in the 2006 National League Divisional Series, which they lost to the St. Louis Cardinals.

Becoming a free agent following the 2007 season, Blum signed a one year contract with the Houston Texans.

1. Full name: Geoffrey Edward Blum
2. Born: April 26, 1973
3. Birth Place: Redwood City, California
4. Position: Second Base
5. Bats/Throws: Switch/Right
6. Uniform Number: 27