How do you make your debut in roles as exalted as the Sugarplum Fairy and her cavalier in “George Balanchine’s The Nutcracker”? And how much does a debut performance count for? The questions recurred this Christmas season at New York City Ballet when the company — investing in its future — gave these parts as opportunities to a series of young dancers from the corps.

Certainly City Ballet revealed its new wealth of star potential among its youngest women and their remarkable variety. As events proved, there is no single solution to the famous role. Since 1954, when Maria Tallchief and Tanaquil LeClercq alternated in it, the Sugarplum has become a different character according to each important ballerina’s interpretation. And success is elusive. Some of the greatest dancers of Balanchine’s day — Suzanne Farrell, Patricia McBride — were at their least legendary in it. And in this era, it took Sara Mearns years before she, magnificently, conquered it.

So this season, it was startling to find that two young dancers making their debuts — scarcely known even to aficionados in the audience — seemed immediately right for this role, Unity Phelan and Ashley Hod. They joined the company in 2013; both are absorbingly handsome in face and figure, with gorgeously elegant line. You have only to look at them to feel the distinction they bring to the Kingdom of Sweets. Ms. Phelan, who danced the matinee Dec. 16, was the more regal and warm of the two: an exquisite performance, with moments of sweeping grandeur.

Through much of the pas de deux, Ms. Hod, who danced Sunday, seemed more guarded in revealing herself. Then came the role’s greatest moment — a sequence of supported pirouettes with rising arms that suddenly end in a backbend toward the audience. Those arms have risen in a spiraling cone, when suddenly the dancer opens herself up in a sudden cascade, with face and shoulders stretching back toward us. Most of these new performers were handsome here, but the secret — ending the backbend with a photograph-like stillness before the phrase rushes on — sometimes seemed to be lost. Yet Ms. Hod, assisted by the expert Adrian Danchig-Waring and arching back with ravishing fullness, was breathtaking: motionless and spectacular for a perfect instant.