The Science of Soccer John Wesson IOP, Philadelphia, 2002. $24.00 paper (199 pp.). ISBN 0-7503-0813-3
The Science of Soccer is a pleasant addition to a long line of sports-related books by English authors, each of whom wants to explain the sound physical reasons why things happen in a particular game. Many of these books are about golf, such as Alistair Cochran and John Stobbs’s The Search for the Perfect Swing (Lippincott, 1968). They encompass, however, a wide range of other sports. The present book compares in spirit with Geoffrey Dyson’s The Mechanics of Athletics (U. of London Press, 1973), but is at once more rigorous and less complete than that book. Similar efforts are popular in the US. Most of those are considerably longer than their English cousins; one thinks, for example, of James Counsilman’s The Science of Swimming (Prentice-Hall, 1968), or Robert Adair’s The Physics of Baseball (3rd ed., Perennial, 2002).
Wesson’s efforts are not as ambitious as those last two are, at least in the parts in which he discusses the physics involved in the game. He devotes only the first third of the book to that discussion, and there he mostly concentrates on the behavior of the ball. He briefly considers the mechanics of the body during the kick, but that subject is better treated in other books–in Dyson’s, for example. For the rest of the book, Wesson reaches into territory that few such books have explored before, including some thoughts on rudimentary game theory, on strategy, and on the economics of the game today. Those parts make interesting reading.
It is sometimes a little hard to tell what audience Wesson writes for. In discussing the physics in the first third of the book, he gives a mostly qualitative account. Except for an extraordinary incorrect paragraph on why balls bounce, fortunately preceded by a correct one, the discussions are insightful and offer the general reader a feeling for the mechanics of the flight of the ball. The treatment suggests that Wesson has made some calculations to buttress his statements, but the suggestions are not obtrusive and do not dominate the discussion. In the second section, in which he branches into other subjects, the arguments are still more or less qualitative, but the presence of model calculations underlying the discussion is more evident. He devises, for instance, a sort of handicapping algorithm, based on team records, that he uses to predict probable game outcomes. In the tradition of good science, he then tests his algorithm against actual play–with good results. In contrast to that excursion, most of the calculations in the section are based on the statistical probabilities of random events. Perhaps the most interesting is a model of the two-dimensional position that the ball traverses across the field during play. The model amounts to a sort of Brownian motion calculation. It’s clever, but the notion that the ball’s motion in a game is simply random might provoke, if not offend, the average fan.
In the last chapter, Wesson summarizes the models he has used for the calculations in the earlier sections. As one would expect from someone with his credentials (he has played competitive soccer and holds a PhD in physics), the models are free of mathematical foolishness. Unfortunately, the commentary explaining them is often opaque. The mathematics in the chapter ranges from the sort of Galilean trajectory analysis common to most introductory physics courses, through a quick introduction to Newtonian mechanics using calculus, to a curious mention of the Fokker–Planck equation. The large spread in levels of sophistication makes much of the chapter mysterious in the eyes of a general audience, for whom he seems to be writing the first part of the book.
I have used books like The Science of Soccer in reading lists for courses about science and sports for a general audience. For the most part Wesson’s book is a rather nice one, but I would not be tempted to include it in such a list because the last chapter would intimidate that audience.
