Yowamushi Pedal, Days (TV) Recommendations
Earnest lead character who has no experience with sports gets roped into it because he wants friends. No one expects much of him but he goes on to impress.
Both anime are sports oriented with a protagonist demonstrating unpredictable and outstanding results that surprises everyone. Also builds up to competing and winning competitions with a variety of characters as well as 1-2 people being the more experienced and supportive friend of the protagonist.