Show caption Hide caption Over time, CBS' "Mom" evolved into a smart buddy comedy centering on a group of friends working together to keep their sobriety - Wendy (Beth... Over time, CBS' "Mom" evolved into a smart buddy comedy centering on a group of friends working together to keep their sobriety - Wendy (Beth Hall), left, Bonnie (Allison Janney), Tammy (Kristen Johnston), Jill (Jaime Pressly) and Marjorie (Mimi Kennedy) - while exchanging insults softened by an underlying love for each other.Robert Voets, Warner Bros. Entertainment Inc. While some shows "jump the shark" – making crazy changes when they run out of ideas, as exemplified by the ridiculous sight of leather-jacketed Fonzie water-skiing over a shark on "Happy Days" – "Mom," from sitcom king Chuck Lorre, effectively reversed that process, employing creative revisions that helped prolong its run as an entertaining series. (However, the disappearance of Christy's kids, while explained, proved awkward.)