The Science of Soccer The Science of Soccer Second Edition John Wesson CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2020 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Printed on acid-free paper International Standard Book Number-13: 978-0-367-33311-9 (Paperback) International Standard Book Number-13: 978-0-367-33484-0 (Hardback) This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www. copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Library of Congress Cataloging‑in‑Publication Data LoC Data here Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com For Olive My favourite football fan Contents Preface ix  1. The ball and the bounce 1  2. The kick 17  3. Throwing, heading, punching, catching, receiving, trapping 29  4. The ball in flight 39  5. The laws 65  6. Game theory 79  7. The best team 97  8. The players 113  9. Economics 127 10. Mathematics 137 Chapter images 183 Bibliography 185 Index 189 vii Preface Football is by far the world’s most popular game. Millions play the game and hundreds of millions are entertained by it, either at football grounds or through television. Despite this the scientific aspects of the game have hardly been recognised, let alone dis- cussed and analysed. This is in contrast to some other games which have received much more attention, particularly so in the case of golf. What is meant by ‘science’ in the context of football? This book deals basically with two types of subject. The first is the ‘hard science’, which mainly involves using physics to uncover basic facts about the game. This ranges from understanding the compar- atively simple mechanics of the kick to the remarkably complex fluid dynamics associated with the flight of the ball. The second group of subjects is diverse. There is the role of chance in deciding results and, more significantly, in influencing which team wins the Premiership or the Cup. Is the winning team the best team? We look at the players and ask how their success varies with age. We also ask, what is the best height for footballers and, with almost incredible results, what is the best time of year for them to be born? Further subjects include analysis of the laws, various theoretical aspects of the play, and the economics of the professional game. In the first nine chapters of the book these subjects are described without the use of mathematics. The mathematical analysis which underlies this description is saved for the tenth and final chapter. Most of the material in the book is original and in many areas the author has made progress only with the ix