This revision of *Jikkyou Powerful Pro Yakyuu 3 - '97 Haru* indicates a post-launch update by Konami. The 'Rev A' designation implies bug fixes, performance enhancements, or minor gameplay adjustments to enhance the player experience.  While the specific changes are often undocumented, it reflects Konami's effort to ensure a more refined game for its players.

Jikkyou Powerful Pro Yakyuu 3 - '97 Haru (Japan) (Rev A)

Jikkyou Powerful Pro Yakyuu 2 (Japan)