Billy Mitchell (EastEnders) revealed in 2006 that the role was extended by "coincidence and chance": "I was offered four episodes and here I am, about 800 later. [...] Ross Kemp (Grant) said that he was leaving, and there was a gap in the Mitchell family, so they brought me back to do stuff towards his leaving. After that they offered me a year." Billy was reintroduced in 1999, making recurring appearances. He was involved in the leaving storyline of Grant Mitchell in October 1999, before returning later in the year as a regular character. When Billy was first introduced, he was depicted as
Jack Kemp because its football team used professional formations and plays, which he hoped would help him to become a professional quarterback. At and , he considered himself too small to play for the USC Trojans or UCLA Bruins, the major Southern California college football programs. At Occidental, Kemp was a record-setting javelin hurler and played several positions on the football team: quarterback, defensive back, place kicker, and punter. Although he was near-sighted, Kemp was tenacious on the field. During his years as starting quarterback the team posted 6–2 and 3–6 records. Kemp was named a Little All-America player one year in