Complex sentence: His professional umpiring career began after he attented the Joe Brinkman Umpire School in 1989, and he worked his way up to the Pacific Coast League for the 1993 season.
Split into simpler sentences: His professional umpiring career began after he attented the Joe Brinkman Umpire School in 1989. He worked his way up to the Pacific Coast League for the 1993 season.