Players of all skill levels can throw the Aerobie Superdisc well & enjoy its stable, accurate flights. Its patented spoiler rim & soft rubber edge were developed when inventor Alan Adler set out to design an enhanced " Frisbee." Conventional flying discs have their center of aerodynamic lift near the disc's leading edge in flight. That's why they tend to roll to the right for right handed throws & to the left for left handed throws. By contrast, the Superdisc's breakthrough spoiler rim centers the disc's aerodynamic lift throughout each flight, making the Superdisc a more stable flyer for throwers of all skill levels.