Complex sentence: In the 1999 season, another catcher prospect Hong Sung-Heon was signed by the Bears upon graduation from college, and his arrival provided further fierce competition for the starting catcher position.
Split into simpler sentences: In the 1999 season, another catcher prospect Hong Sung-Heon was signed by the Bears after graduating from college. The arrival of Hong Sung-Heon provided further pierce competition for the starting catcher position.