Professional baseball in the United States has a long history, as both the American and National Leagues have played since the 1901 season. Baseball from the beginning collected statistics, so most of the basic statistics such as counts of at-bats, hits, runs, home runs, strikeouts, and walks are available for all players since 1901. In this chapter graphs are used to explore patterns of rates of these basic statistics over time – these patterns help us learn about the history of baseball. The first part of this chapter focuses on team offensive statistics such as the number of runs or home runs hit by a team in a baseball game. Baseball is a competition between the offensive team and defense team and these plots show that the balance of this competition has drifted between the offense and the defense over baseball history. For example, we will learn that strikeouts per game are currently at an all-time high suggesting that pitchers currently have an advantage in modern baseball.