Sisters Are Two of a Kind, Like Those 1960s Cousins Two television series, a half-century apart. In each, one young actress plays two separate look-alike characters. But here's a difference you gotta love. In the older series, "The Patty Duke Show," several episodes revolved around the teenage Patty Lane's relationship with a star basketball player. In the newer show, "Liv and Maddie," Maddie is a star basketball player. "Liv and Maddie" is a gentle, moderately amusing comedy that arrives Sunday on the Disney Channel, and it's a good one for grandparents to watch with their grandchildren. The kids will probably get some laughs out of the show, and the oldsters will enjoy looking for points of comparison to Ms. Duke's sitcom, which ran from 1963 to 1966. Ms. Duke played identical cousins, one a sophisticate with a British accent, the other a classic American teenager from the early rock "n" roll era. The setup of "Liv and Maddie" is a bit different - the title characters are twins, both played by Dove Cameron - but the dynamic is the same. Maddie is a typical Wisconsin 15-year-old who in the premiere is elected captain of the high school basketball team. Liv has just returned to live at home after starring for several seasons in some kind of TV show. Ms. Cameron does a decent job with the mix of down-to-earth and diva, and the premise gives the writers plenty of opportunities. In the premiere Liv, who is not at all athletic, joins the basketball team briefly. "What position do you play?" a teammate asks. "I'm usually the lead," she says. Yes, grandparents, somewhere in the last 50 years, Hollywood replaced Europe as our source for worldly teenagers. That may not be progress, but back in the day, in many towns neither Cathy nor Patty Lane would have had a basketball team to join. Liv and Maddie Disney Channel, Sunday nights at 8, Eastern and Pacific times; 7, Central time. Produced by It's a Laugh Productions. Created by John Beck and Ron Hart. Mr. Beck, Mr. Hart, Andy Fickman, John Peaslee and Betsy Sullenger, executive producers. WITH: Dove Cameron (Liv and Maddie Rooney), Joey Bragg (Joey Rooney), Tenzing Norgay Trainor (Parker Rooney), Benjamin King (Pete Rooney) and Kali Rocha (Karen Rooney).