Many television series have lost and gained characters across their lifetime, but when Kirstie Alley took over from Shelley Long as the female lead of "Cheers" in 1987, it was something epochal, almost a reboot, a new lease on life. Long's Diane Chambers was a runaway bride, cerebral, willowy, blond, mathematically fated to be mated with Ted Danson's bartender-proprietor Sam Malone — and they were indeed together off and on through her five seasons.
As Rebecca Howe, who came into the series as Sam's new boss — he had sold the bar to a conglomerate — Alley, who starred in the next six seasons, was something entirely different: dark, solid, physical, throaty, with a gift for slapstick and the license to go big where Long had been contained, and — to his endless frustration — not interested in Sam at all.
I have never seen any of the three "Look Who's Talking" films that Alley, who died Monday at age 71, made with John Travolta during and just after the run of "Cheers," but I can only assume that she's great in them, because I never saw her otherwise, even in shows and parts that were less deserving of her presence, less supportive of her talent. "Cheers" is one of the best written comedies in television history, however, and the combination of actor and role created the part for which she is rightly best remembered.