Hoop Days and Hajime No Ippo to name a couple that have been put up on Silent Divergence. These two I would consider some of the better sports based anime shows.
Big Windup! didn't take quite as much of an athletic approach. Much of the story is focused around a very self conscious pitcher named Mihashi. He has had to transfer to Nishiura High in order to escape the nepotism that allowed him to pitch at his previous school, Mihoshi Academy, which also also happens to be owned by his grandfather. It turns out that Mihashi isn't really a bad pitcher at all and that the lack of support from his team is what has caused him to believe that he is such a bad baseball player. The premise behind the entire series is helping Mihashi to feel that he is part of the team and that he has earned his spot as the ace pitcher for Nishiura.
The actual development of the characters takes place over two baseball games and some practices. The series does drag along a little because of this. It is very reminiscent of the problem that Dragon Ball Z faced where some fights would take 5-10 episodes in order to complete. The same is present in Big Windup! The two games played are between Mihoshi Academy and Nishiura, and Tosei High and Nishiura. I won't tell you the outcome of the games, but the first game takes about 6 episodes to complete. The second game runs through almost 13 episodes (or half of the series).
Although I do like the concept of taking time to develop the characters and story while not rushing the end, this was a little too long drawn for me. The story was great, and the show was very entertaining. The hardest part was actually to stop watching for the day because you would literally have to pause in the middle of the game. I often found myself becoming curious as to the outcome of the next episode and this gave the feeling of an incomplete experience while trying to watch the whole series.
My only two criticisms of this show were that the music was very repetitive and many of the animation sequences were reused far too many times. Both of these issues tended to arise during the scenes where the crowd activity is being shown during the final game.
I would have to say that Big Windup! is definitely a marathon type of show. If you are looking for something to watch an episode here and there, keep looking. Because the show touches on so many themes and meanings, along with the design of the episode structure, it is a very deep show and requires you to be ready to pay attention. I can honestly say that I was entertained with this show and I do recommend adding it to your collection if you are a fan of sports anime.