What is "cinderellas"

Usage examples of "cinderellas".

All high-risk Cinderellas would have gone to the ball under Alec’s wand: the trick was in choosing only those who would keep an eye on the clock and deliver the crystal goods.

Beat her, and I'm not just the local champion -- our lone warrior against the nation's best -- but I'm also one of the year's Cinderellas, guaranteed all the attention that comes to statistical flukes.