Major S5

Both anime are about baseball, both main characters are not intelligent however they are excellent at baseball and get stronger as the story progresses. However Major focuses more on the protagonist while diamond no ace goes more in depth into the entire team and the other teams. 

Both shows feature protagonists who although overly excel in their respective fields, still learn new things as new challengers approach. Both shows also have hints of romance and tackle themes such as dreams/future 

Both of them are baseball related and have a main female character that is a possible love interest for the main character. 

these two are the same becauae it talks about baseball and the main characters are both pitchers their "ladies" are their child hood friend and they have friends cheering them on and its about some insane love and passion for baseball. 

While Major revolves around Baseball, Capeta's about racing. Despite being sports, the essence of both stories are about a boy who struggles through all hardships chasing their dreams. Its another heart warming, motivating series worth watching. Capeta, left with a widowed father had forced himself to be self reliant from young. Surviving poverty, Capeta has given up on indulgence in every way he could. What he just couldn't give up, was his desire to race. Even when he knew that racing was not a sport for the impoverished. With no money, no sponsor, Capeta fought the odds supported by his friends and fueled by the desire to carry on- no matter how.  read more 

It's about baseball too and it's really good. Both main characters are pitchers and they love to challenge others. Tokuchi Toua is super-intelligent and has an unusual ability, Goro Shigeno is really talented player, always learning new throws and working on his physical abilities. One Outs shows more about unusual strategies, tricks, kind of "mind games". Major concentrates on courses of matches and physical abilities.  

Both main characters are determined and have a real passion for the game that inspires the team around them to perform better. These are sport animes but the aspects and emotions of the human being are the real deal here.