a mathematician at the ballpark
Reviewed by Brett Conway, Namseoul University, Korea
MAY 2, 2007 archive
Are You a BRA Type or a SLOB?:
A Review of Ken Ross’s A Mathematician at the Ballpark
With the new baseball season starting, many activities begin anew – fantasy leagues, the Yankees dominance of the AL East (sorry Sox fans), the analysis of importing expensive players like Dice-K from overseas, and Barry Bonds’s chase for Henry Aaron’s homerun record. Until April 1, baseball fans just had to wait to find out whether or not any of these events would happen or whether Dice-K or Barry Bonds could succeed in achieving their respective goals. They had to wait unless they bought a copy of Ken Ross’s A Mathematician at the Ballpark: Odds and Probabilities for Baseball Fans, a look at baseball statistics and how and why some are important and others are not. For those wanting to knowing whether on-base percentage or slugging percentage is the important statistic, for those wanting to get into the nitty-gritty of probability analysis, or for those uncertain about the new baseball year and want to find safety in numbers, this book is for you.
The book is divided into a preface, eight chapters, and three appendices. The chapters use statistics to decide the best hitter, to examine baseball odds, and to explore strategies for betting on professional baseball among other topics. The appendices, as expected, are for those who really want and understand the statistics and formulas Ross has used throughout the book. One on fantasy baseball, I’m sure, would be a good tutorial for those who participate in the fantasy leagues.
But other chapters, I feel, don’t belong in a book about baseball. Chapters about buying lottery tickets or knowing when one should stop betting in the casino are clearly out of place. They seem to be nothing more than filler in a book that barely reaches two hundred pages including index. They should’ve been removed or recast in a book about betting in general.
Despite those extra chapters, a baseball fan will learn a lot about baseball statistics from this book. Baseball is more dependent on statistics for decision making than maybe any other sport. And this book gives some highlights. Ross discusses what is more important for measuring a hitter’s worth. He brings up the usual stats such as hitting percentage (“hitting proportion” is a more accurate term, Ross insists), on-base percentage, and slugging percentage, dismissing them as only a part of a bigger picture. Instead he offers OPS and BRA or SLOB. OPS is found by adding a hitter’s on-base percentage to his slugging percentage. Ross looks at the two Japanese hitting sensations, Hideki Matsui and Ichiro Suzuki, to show that although Ichiro had a much better batting average, overall the two Japanese sluggers had about the same kind of season when OPS is taking into consideration. On the other hand, BRA or SLOB is a product of on-base percentage and slugging percentage, thus it gives slightly greater weight to slugging percentage and the number of runs scored. Ross, though, figures either OPS or SLOB works well enough.
Some discussions explore statistics generally, such as probability and odds. Others look at specifics like why so many world series end in 4 or 7 games more often than probability allows, why a batter batting .400 won’t consistently hit safely 4 out of every 10 times he steps to the plate, how to measure whether a breakout year or a yearlong slump is statistically significant, and how to bet wisely whether with a gambling site or a friend.
This book, however, is full of statistics, equations, proofs, and analysis. To get through it requires paper and pencil and some patience unless the reader comes to it with a background in statistics. Nonetheless, the arguments Ross makes about what is likely and unlikely and what is important and unimportant when players are pitching and catching on the diamond does add to this fan’s appreciation of decisions on the baseball field.
Ken Ross. A Mathematician at the Ballpark: Odds and Probabilities for Baseball Fans. 2004. New York: Plume, 2007. 208 pp. ISBN 978-0-452-28782-2.
Copyright © 2007 by Brett Conway.