Physics of Baseball: Third Edition, Revised, Updated, and Expanded by Robert K. Adair

From the Publisher

Blending scientific fact and sports trivia, Robert Adair examines what a baseball or player in motion does-and why. How fast can a batted ball go? What effect do stitch patterns have on wind resistance? How far does a curve ball break? Who reaches first base faster after a bunt, a right- or left-handed batter? The answers are often surprising — and always illuminating.

This newly revised third edition considers recent developments in the science of sport such as the neurophysiology of batting, bat vibration, and the character of the "sweet spot." Faster pitchers, longer hitters, and enclosed stadiums also get a good, hard scientific look to determine their effects on the game.

Filled with anecdotes about famous players and incidents, The Physics of Baseball provides fans with fascinating insights into America's favorite pastime.

New York Times Book Review

Fascinating and irresistible.

Wall Street Journal

An absolutely wonderful compendium of little know fact about the national pastime.

Product Details

• Table of Contents
• Read an Excerpt

Table of Contents

Read an Excerpt

A small, but interesting, portion of baseball can be understood on the basis of physical principles. The flight of balls, the liveliness of balls, the structure of bats, and the character of the collision of balls and bats are a natural province of physics and physicists.

In his analysis of a real system, a physicist constructs a welldefined model of the system and addresses the model. The system we address here is baseball. In view of the successes of physical analyses in understanding arcane features of nature--such as the properties of the elementary particles and fundamental forces that define our universe (my own field of research) and the character of that universe in the first few minutes of creation-it may seem curious that the physics of baseball is not at all under control. We cannot calculate from first principles the character of the collision of an ash bat with a sphere made up of layers of different tightly wound yarns, nor do we have any precise understanding of the effect of the airstream on the flight of that sphere with its curious yin-yang pattern of stitches. What we can do is construct plausible models of those interactions that play a part in baseball which do not violate basic principles of mechanics. Though these basic principles--such as the laws of the conservation of energy and momentum-severely constrain such models, they do not completely define them. It is necessary for the models to touch the results of observations--or the results of the controlled observations called experiments-at some points so that the model can be more precisely defined and used to interpolate known results or toextrapolate such results. Baseball, albeit rich in anecdote, has not been subject to extensive quantitative studies of its mechanics, hence, models of baseball are not as well founded as they might be.

However connected with experience, model and system-map and territory-are not the same. The physicist can usually reach precise conclusions about the character of the model. If the model is well chosen so as to represent the salient points of the real system adequately, conclusions derived from an analysis of the model can apply to the system to a useful degree. Conversely, conclusions-although drawn in a logically impeccable manner from premises defined precisely by the model-may not apply to the system because the model is a poor map of the system.

Hence, in order to consider the physics of baseball, I had to construct an ideal baseball game which I could analyze that would be sufficiently close to the real game so that the results of the analysis would be useful. The analysis was easy; the modeling was not. I found that neither my experience playing baseball (poorly) as a youth nor my observations of play by those better fitted for the game than I ideally prepared me for the task of constructing an adequate model of the game. However, with the aid of seminal work by physicists Lyman Briggs, Paul Kirkpatrick, and others, and with help from discussions with other students of the game, such as my long-time associate R. C. Larsen, I believe I have been able to arrive at a sufficient understanding of baseball so that some interesting conclusions from analyses of my construction of the game are relevant to real baseball.

In all sports analyses, it is important for a scientist to avoid hubris and pay careful attention to the athletes. Major league players are serious people, who are intelligent and knowledgeable about their livelihood. Specific, operational conclusions held by a consensus of players are seldom wrong, though-since baseball players are athletes, not engineers or physicists--their analyses and rationale may be imperfect. If players think they hit better after illegally drilling a bole in their bat and filling it with cork, they must be taken seriously. The reasons they give for their "improvement," however, may not be valid. I hope that nothing in the following material will be seen by a competent player of the game to be definitely contrary to his experience in playing the game. Honed by a century of intelligent trial and error, baseball must surely be played correctly--though not everything said about the play, by players and others, is impeccable. Hence, if a contradiction arises concerning some aspect of my analyses and the way the game is actually played, I would presume it likely that I have either misunderstood that aspect myself or that my description of my conclusion was inadequate and subject to misunderstanding.

Even as the results discussed here follow from analyses of models that can only approximate reality, the various conclusions have different degrees of reliability. Some results are quite reliable; the cork, rubber, or whatever stuffed into holes drilled in bats certainly does not increase the distance the ball can go when hit by the bat. Some results are hardly better than carefully considered guesses: How much does backspin affect the distance a long fly ball travels? Although I have tried to convey the degree of reliability of different conclusions, it may be difficult to evaluate the caveats properly. By and large, the qualitative results are usually reliable, but most of the quantitative results should be considered with some reserve, perhaps as best estimates.

In spite of their uncertainties, judiciously considered quantitative estimates are interesting and important; whatever their uncertainties, they often supplant much weaker-and sometimes erroneous--qualitative insights. Consequently, I have attempted to provide numerical values almost everywhere: sometimes when the results are somewhat uncertain, sometimes when the numbers are quite trivial but not necessarily immediately accessible to the reader.

As this exposition is directed toward those interested in baseball, not physics, I have chosen to present quantitative matters in terms of familiar units using the English system of measures distances in feet and inches, velocities in miles per hour (mph), and forces in terms of ounce and pound weights. I have also often chosen to express effects on the velocities of batted balls in terms of deviations of the length of a ball batted 400 feet (a long home run?) under standard conditions.

To express the goals of this book, I can do no better than adopt a modification of a statement from Paul Kirkpatrick's article "Batting the Ball": The aim of this study is not to reform baseball but to understand it. As a corollary to the statement of purpose, I must emphasize that the book is not meant as a guide to a player; of all the ways to learn to throw and bat a ball better, an academic study of the mechanics of the actions must be the least useful.