If you've ever read Tom Clancy or Stephen King, you know that they sometimes go into very specific technical and psychological details. You could easily skip those paragraphs, and not miss a beat with the whole book. But, by reading those details, you gain an extra level of appreciation.

There are several major tools that we will be using throughout this book. In this chapter, we will introduce and describe them as completely as possible, as well as explain how they all relate to each other. Since these tools are used in some shape or form throughout the book, we find it more convenient for us (and perhaps more palatable for you) to dump/explore them here.

As with the King and Clancy novels, feel free to skip this chapter in its entirety if the technical presentation does not appeal to you.

Base/Out States

Everything about baseball (for that matter, everything about anything) is about context. All actions, events, data, and information are meaningless without context. And we don't mean meaningless in some theoretical sense, but in an actual, practical sense. Consider these words that you are reading right now. The primary context is the English language. You can expand that context to include the subject matter, baseball. Without understanding English and baseball, the words on this page and throughout the book would be gibberish to the reader.

So how do you describe baseball? For starters, a baseball game consists of nine (or more) innings, each of which is more or less equivalent in terms of what can happen. So we can think of the inning as the fundamental building block of the game. What contexts do we find within an inning? The most important is that you have three outs per inning. The second-most important is that you have three bases at which players can rest between batters on the way to scoring by touching a fourth base (home plate), and that each base will either be occupied or open. So combining these two contexts, you can have one out and men on first and second, two outs and a man on third, or any other combination of number of outs and occupied bases. The total number of potential combinations that you can have is exactly 24.

We refer to these 24 combinations as base/out states. These give us the context with which we can understand the events that unfold during an inning.

The inning always starts with the same initial base/out state: bases empty and no outs. The inning always ends when a team accumulates three outs. We can think of this as a 25th base/out state, though it differs from the other 24 because nothing can happen once this three-out state is reached.

From the start of the inning to the end of the inning, you will transition from base/out state to base/out state as the events unfold—hits, outs, baserunning, and so on. Along the way, you can pile up runs until you reach that final state (end of inning).