Princess Nine is a twenty-five episode Anime (25 minutes each) with a Baseball theme, but it is really a drama at its core. Animation is pretty good!! But the story is quite simple.
I'd go as far as saying that you can watch at a few episodes of the beginning to get a feel for the main characters (not the rest of the case), and the final 3 (last game), and you'd have a complete view of the story it wants to tell. It's somewhat disappointing that the ultimate obstacles the girls face are purely internal and based on flimsy emotional changes to a couple of aces (bringing the entire team down).. and so, they are equally easily "solved".
But it's still a decent watch.. it just didn't resonate with me on any level.
If you'd like to watch a Baseball Anime, there's no better than "One Outs"!