MacGyver The new episode “Mac & Jack” uses flashbacks to recall how MacGyver and Jack (Lucas Till, George Eads) first met. 8 p.m. CBS
Crazy Ex-Girlfriend Rebecca (Rachel Bloom) is starting to see a pattern in her life and relationships as the kooky musical comedy presents its midseason premiere. 8 p.m. KTLA
Child Support Host Fred Savage (“The Wonder Years”) quizzes grown-ups, while comic Ricky Gervais puts the same questions to a group of young kids in this new game show. 8 p.m. ABC
Treehouse Masters The builders are back to construct even more outrageous creations in this reality...