Michael A. Humphreys advises on tax aspects of international capital markets transactions at Ernst & Young LLP.

The book of the season . . . comes from Michael Humphreys . . . who has spent years meticulously extracting reads on historical defensive performance from the flawed and fragmentary numbers we have to go by, and he now offers the definitive work on the subject . . . A careful, thoughtful system that will make you appreciate all the more the genius of the late Yankees second baseman Joe Gordon or the peripatetic and vastly underrated outfielder Kenny Lofton . . . A representation of the future of statistical sabermetrics, which in years to come is quite likely to become more focused less on telling the future than on wresting meaning out of the past." -- Tim Marchman, The Wall Street Journal

"Excellent." -- David Schoenfeld, ESPN ("Sweet Spot" blog)

"Humphreys writes capably and makes the math-heavy parts as readable as anyone could. The outcome should attract all dedicated baseball fans and stat hounds." -- Library Journal

"Michael Humphreys does for fielding what Neil deGrasse Tyson does for astrophysics: he takes an incredibly complex subject and makes a reader who once felt dumb feel smart. He has cut through the cloud of my unknowing and helped me to understand what major league fielding really is and how it can be quantified. Wizardry is the best book yet on the subject." -- Allen Barra, writer for The Wall Street Journal

"Fielding is the hardest aspect of baseball in which to rate performance. In his fascinating book, Michael Humphreys should get the Gold Glove for historical fielding evaluation. With carefully derived formulae, he rates Aaron, Clemente, Gordon and Hooper as saving 100+ runs more than does Total Baseball, while Mazeroski and Ozzie Smith saved their teams over 100 fewer. And that's just among Hall of Famers! Taken seriously, as it should be, this book will substantially shake up our all-around rankings of players." -- Michael J. Schell, Moffitt Cancer Center, author of Baseball's All-Time Best Hitters and Baseball's All-Time Best Sluggers

"Wizardry is a very engaging book. Out of all of the modern methods of evaluating fielding, [the method introduced in Wizardry, DRA,] is the one method where readers can duplicate the results. The defensive runs produced by DRA match up well with [published defensive runs estimates based on proprietary data]. While all of these defensive metrics can vary widely from season to season, they have their biggest impact when evaluating a player's defensive career. In a perfect world, the gatekeepers to the Hall of Fame will start to rely on defensive metrics such as DRA, rather than how many Gold Gloves a player won, to assess a player's defensive contributions on the field."--Philip A. Yates, The American Statistician