1) “Mom,” 9 p.m., CBS. Even after a big loss – the departure of Anna Faris as Christy – this remains one of TV’s best comedies. Tonight, Jill (Jaime Pressly, right) worries that her romance with Andy (Will Sasso, left), the beefy cop, is over; her friends soon join her on a stake-out. That part is fairly good, but the big laughs come from Adam – Bonnie’s husband and Andy’s friend. When it comes to social signals, he’s genuinely clueless.
2) “Young Sheldon,” 8 p.m., CBS, and more. After a slow stretch – new shows on only two of the last eight Thursdays – CBS’ comedy block is back. That starts well, with Sheldon’s college-orientation crumbling in funny ways. Then a terrific “B Positive” (8:30) has Gina (the delightful Annalaeigh Ashford) facing a psych exam before she can be a kidney donor. After the excellent “Mom” (see above), “The Unicorn” (9:30) has an episode that starts weakly, then ends with solid laughs.
3) “Mr. Mayor,” 8 p.m., NBC. This has quickly become an excellent show, fueled by great supporting characters – the no-nonsense Arpi (Holly Hunter) and the all-nonsense Jayden (Bobby Moynihan). Tonight, they’re forced to work together. That’s part of a strong alternative comedy route, with NBC’s “Superstore” at 8:30, followed by Fox’s “Call Me Kat” and “Last Man Standing,” at 9 and 9:30.
4) Walker” debut, 8 p.m., CW. For nine seasons, “Walker, Texas Ranger” had Chuck Norris as Cordell Walker, a karate-kicking force for justice. Now this prequel has Jared Padalecki as a Walker who is younger and taller and still semi-shaven. The difference is that this Walker is soon encased in grief; he drinks too much, ignores his kids and worries his family. Fortunately, he has a blunt-talking, Latina partner at work who has her own fight moves. It’s a mixed start to a promising series.
5) “Legacies” season-opener, 9 p.m., CW. As the headmaster tries soothes his students, Alyssa reminds him about “your daughter, who murdered me and held the entire school hostage.” Good point. Alyssa is now unmurdered (it’s that kind of show), but bears a grudge. When a field day is interrupted by killer knight, there’s no hope. (Or no Hope; she’s in a coma and Landon is – for now, at least – dead.) As strange as this all sounds, this is solidly crafted, a strong (if weird) bit of youthful fantasy.