ABSTRACT
A baseball game is won when one team scores more runs than the opposing team. The ratio of a team's total runs and total runs allowed has a strong relationship to the ratio of wins to losses. Runs expectancy is a measure of the opportunity to score during an inning given a particular number of outs and runners on base. Graphs help us understand the pattern of run scoring, and the pattern of expected runs for different numbers of outs and runners on base. A team's potential to score runs will change depending on the game situation. A plate appearance is a turn at-bat for a particular player. In a plate appearance, there are four types of hits: a single, double, triple, and home run. This chapter provides a graphical view of runs expectancy which is one of the building blocks for understanding the values of baseball plays. Runs values of plays have many applications in baseball analytics.
