But a kid who does yo-yo tricks? Just ask Yo-Yo Mike. Or, as he’s known at Flambeau Products Corp., Michael Caffrey, director of marketing and sales for Duncan Toys Co., a division of Flambeau.

June 6 marks National Yo-Yo Day, a celebration of one of the world's oldest and most enduring toys. The date honors the birthday of Donald F. Duncan Sr ... ve created a new trick." ...

Mr. Flores had been discovered a few years earlier by Don Duncan Sr., a Chicago toymaker who sold tops until he watched Mr. Flores perform yo-yo tricks for neighborhood children. Mr. Duncan ...