I automatically think of tumbling when I think of Rookies and vice versa. All trouble boys learning a sport together. They learn to build a friendship with their members and learn to love the sport.
Both dramas are about a sports club making a come back. (Baseball for Rookies; Rythmic Gymnastics for Tumbling) Plus, there are the required cute Yankees. xD Rookies has a teacher that is the influence to change while Tumbling is more of a combined effort. You can't help cheering both teams on and desperately hope they reach their dreams.
both have delinquents and they a passionate teacher supporting and believing in them. Same concept, one is about baseball and the other about life. You'll love Rookies.
Both titles deal with a similar issue: an inspirational teacher who makes his students believe again in themselves and their dreams.