This is a book about baseball, and in particular how the common ways of judging players, at least at the time of writing, were giving the wrong signals to managers and teams about who were the best players.
Michael Lewis follows the Oakland A’s and their management, particularly the General Manager Billy Beane, to see how with a low budget, and a lot of data analysis, they are able to out-perform by finding players who the market was under valuing. He intersperses their story with various characters who led the development of baseball statistics, and also spends time in depth with a few under-appreciated players the Oakland A’s bought.
Where Lewis investigates the incorrect judgement of players he describes three main errors. First, judging without statistics and instead by instinct, for
Instance about which young players will develop best; and then with regards to statistics both not looking at the right ones, and not being able to calculate the right thing. For example, the A’s found on-base percentage was a statistic that contributed highly to the team performance but which was ignored by most teams, so they could focus recruiting here for cheap players who would build a strong team.
Lewis emphasises that what he is describing is not new knowledge, as it had mostly been around for decades, but it was the first time a Major League team had rigorously applied this knowledge to their decision making. Following the success of the A’s, and this book, the analysis is now much more commonly used across the big teams.
This book is a very enjoyable read. I don’t know much about baseball, but only minimal knowledge and an interest in sport is required to follow the book. While set around baseball it is more an insight into how easy it is for a whole structure to be set up on sub-optimal decision making, and what is needed to change things.