This book describes a new baseball statistic called GPA (Gross Productivity Average). The GPA measures how many runs a batter creates for his team or how many runs a pitcher prevents the opposing team from scoring by comparing each player's production to that of the average major league player from 1997 to 2009. The GPA is reported on a scale similar to that used for batting average which makes it is easy to understand. Each player's GPA can be accurately adjusted to take into account his contributions on the base paths and the ballparks in which he played.
The most realistic computerised baseball game simulator ever described is used to show that GPA is an almost perfect measure of a player's productivity. The baseball game simulator and GPA are used to settle controversies in baseball strategy such as (1) how to construct the optimal lineup, (2) when a hitter should be intentionally walked, and (3) when a sacrifice bunt or stolen base be attempted. The effect steroids had on the game are quantified using GPA. The information in this book will allow everyone from baseball professionals to fans to better be able to compare players' performances statistically.