The story is about Hyuma Hoshi, a promising young baseball pitcher who dreams of becoming a top star like his father Ittetsu Hoshi in the professional Japanese league. His father was once a 3rd baseman until he was injured in World War II and was forced to retire. The boy would join the ever popular Giants team, and soon he realized the difficulty of managing the high expectations. From the grueling training to battling the rival Mitsuru Hanagata on the Hanshin Tigers, he would have to take out his best pitching magic to step up to the challenge. 
(Source: Wikipedia)

Based on the novel "Kyojin no Hoshi" by Kajiwara Ikki (Story), Kawasaki Noboru (Art), published in the year 1982.

Mitsuru Hanagata, a pitching prodigy, injured his shoulder in a little league match and withdrew from baseball. His shoulder should have healed, but in a match against a baseball club full of hooligans, he realizes that his shoulder is permanently injured. He will never be able to pitch again. So he changes his focus to become a fearsome batter instead!

A special episode of Takehiko Maeda's world rivals where Atom and Hoshi compete in a baseball match. 
 
Notable for being one of the oldest anime crossover works in Japan.

One day, at the Giants' Tamagawa ground, Egawa was throwing a simulated game in front of Manager Nagashima, when suddenly a stranger stepped into the box and mowed down Egawa's pitches. His name is Hono Mizuki. He was a player who had to move from one school to another due to his short temper getting into fights, so he never caught the eye of any scouts despite his outstanding ability. Osamu Sawada, a freelance talent scout, was asked by Manager Nagashima to investigate. He tested Mizuki first against Hyuma Hoshi, and then Mitsuru Hanagata and Hosaku Samon both had trouble hitting Mizuki's pitches, showing that he had pro-level stuff. Mizuki's competitive spirit is reignited. Mizuki and his best friend set their sights on joining the ranks of pro baseball together.
 
(Source: Amazon.jp, translated)
 
Note: Release date information are based on the tankoubon volumes.