"If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle." --- Sun Tzu, Art of War
Baseball, perhaps more than any of the other major sports, is a game of information. The season is longer, which allows for more compilation of data. The stop-start nature of the game allows for the analysis of data from a whole host of scenarios. The changing of outcomes based on the handed-ness of players causes data fields to double in size.
Then add in that baseball has the most robust minor leagues of the four sports and you can start to trendline the future performances of players over the course of their 3-5 years in the minors.
When you take all this into account, a baseball team would be remiss to not know every intimate detail of their division opponents' operations. Once you ...