⚽Expected Goals and Net Gains

‘Expected Goals: The Story of How Data Conquered Football and Changed the Game Forever’ by Rory Smith (2022)

‘Net Gains: Inside the Beautiful Game’s Analytics Revolution’ by Ryan O’Hanlon (2022)

Why hasn’t someone written ‘Moneyball’ for football? Given the greater availability of data and the rise in the use of analytics in the sport, it felt like only a matter of time before a Billy Beane like figure emerged to educate the masses in how the game is really played and what performance attributes are really valuable.

Football, however, seems to be much too secretive for any club to give away their secrets or to make the specifics of what they do quite as public as Beane was willing to do in Moneyball. But there are other reasons too for why the data revolution in the sport has been much slower – the greater complexity of football relative to baseball, the lack of data available to amateurs and the general public, and the low scoring nature of the game.

So in the absence of a Billy Beane (even though Beane himself is now heavily involved in football), football needed its own Michael Lewis to poke around and explain the rise in the use of data and analytics in football to the masses. Thankfully, it found two such authors resulting in these two excellent books published last year.

Both Expected Goals and Net Gains tell a broad story of a ground up evolution where smart people either with an interest in both data and football, or simply with an eye to making money, began to explore this space and make strides in both the collection and analyses of data on football matches. The influence of Moneyball on most people profiled in both books makes it clear that impact of Lewis’ book has spread far beyond baseball.

Expected Goals by Rory Smith has garnered significant praise in the UK and has been shortlisted for a bunch of football/sports book awards. Smith’s book is about people not data or formulae – he focuses on the analysts, academics and executives who have sought to expand the use of analytics in football rather than what the data says about the game. It’s a very England focused book largely looking at people who worked within English clubs but touching on the wider world occasionally. Smith tells the story of how data began to be collected in greater volume by Opta and Prozone and of some of the early pioneers who started to try and turn the data into useful insights.

Expected Goals

A significant portion of Expected Goals focuses on Chris Anderson, a professor and the author of ‘The Numbers Game: Why Everything You Know About Soccer Is Wrong’ and his attempts, ultimately not quite successful, to find a backer to buy a football club and turn it over to him and a data led approach. The strength of the book is undoubtedly Smith’s exceptional ability to tell a story (for evidence just read this wonderful piece in the NYT) and keep a reader engaged. However, the Anderson subplot is given too much space. It’s an interesting story and, while relevant to the topic (especially on the sport’s resistance to change), it’s ultimately much more about the business of football than the revolutionary use of data.

Net Gains by Ryan O’Hanlon is by contrast a very American book. Not just written by an American and with an American audience in mind (hence the use of Americanisms like roster, cleats, overtime etc.), it also focuses much more on America/Americans – both through telling the story of some Americans involved in football analytics and in drawing parallels between football and other US sports. O’Hanlon applies a wider lens than Smith by also looking in more detail at broader off-pitch issues (like the research that shows higher wages = trophies) rather than a narrower focus on the collection and use of on-pitch data.

O’Hanlon also discusses in more detail what football data actually says and some of the specific uses of data – to improve set-pieces, to evaluate players who aren’t midfielders, to track physical performance and effort etc. O’Hanlon is also coming at the story partly as a former player and partly as a journalist – he is genuinely curious what the numbers say as well as in building the broader narrative.

My only criticism of Net Gains is the poor choice of narrator for the audiobook version – someone who doesn’t know how to pronounce familiar football names like Arsenal, UEFA or Jose Mourinho probably shouldn’t be reading a book full of familiar football names. I quit the audiobook and switched to hardcopy pretty quickly.

Net Gains (Hardcover) | ABRAMS

The evolution of one particular stat (expected goals or xG) is central to both books. It is undoubtedly the public face of the data revolution in football and it’s various origin stories and evolutions are covered well – Smith profiles the guy who designed the version seen on TV while O’Hanlon profiles the guy who coined the acronym xG.

For both books, the challenge remains the absence of a Billy Beane figure willing to spill the details. Hence both struggle with the question of which clubs can we identify as successfully using data and analytics to outperform expectations. O’Hanlon goes into more detail than Smith on the fascinating experiment at FC Midtjylland and Brentford with a particular focus on the little things they worked on like set pieces and use of data in recruitment. Other clubs seeking to use analytics more centrally are identified and discussed, like Fulham, but ultimately both books point to Liverpool as probably the best example of a top level team incorporating analytics into winning a big European league.

In reading both books, and despite the overly bold subtitle to Smith’s book, it becomes clear that the use of data and analytics in football has a long way to go. While its use in recruitment appears to now be standard practice, there remains plenty of scope for revolution in the use of data to amend how a team trains and plays. Where the other limits of this approach will ultimately lie remains to be seen as the complexity of football comes up against ever increasing brain and computer power.

Expected Goals and Net Gains complement each other very well. While there is inevitably some crossover, it is more limited than I would expect and only one particular analyst is heavily featured in both. In other areas where one book just touches on a topic the other dives deeper in a satisfying way. Highly recommend them both.

‘Loose Balls: The Short, Wild Life of the American Basketball Association’ by Terry Pluto (1990)

The American Basketball Association was as an upstart professional league which lasted 9 years before eventually merging with the NBA in 1976.  Well, 4 teams were absorbed into the NBA –  the other 2 teams were left to die (a well-compensated death) and 4 other ABA teams had already folded.

Loose Balls is an oral history of the ABA, the crazy stories, and the impact it ultimately had on the NBA.  It’s remarkable that the ABA survived 9 years with almost no television exposure and very scant newspaper coverage.  The lack of a strong written or video record meant that Pluto wisely chose to write an oral history detailing the often contradictory but always entertaining memories of the key characters in the ABA story.

The ABA’s formation seemed to have been quite haphazard.  In many ways it came into existence because of one man, Dennis Murphy’s, determination to set up a sports league.  Key decisions such as the use of a red-white-and-blue ball and the introduction of a 3 point shot were made on whim rather than being part of a grand design.

The book is exceptionally funny because the characters involved and the shenanigans they got up to funny, bizarre and entertaining.  The story is a wild ride of crazy characters, marketing stunts and, importantly, some very good basketball players.  The business side of the story is also fascinating as teams scrambled to survive and to try and pressure the NBA into a merger.

All of those interviewed by Pluto share the view that the ABA fundamentally changed professional basketball.  These changes included the move to a faster paced game, the 3 point shot, the drafting of younger players and the overall focus on entertainment.   It’s also remarkable just how successful many of the ex-ABA players were after crossing over to the NBA.

There is something I find incredibly interesting about attempts to create a new sports league rivaling a well-established league.  It seems like a crazy idea doomed to fail.  Jeff Pearlman’s recent Football for a Buck brilliantly told the crazy story of the failed United States Football League. And Vince McMahon’s determination to bring back the XFL in 2020 shows there will always be dreamers willing to risk big bucks to break the monopoly of major sports leagues.

Loose Balls covers all 9 seasons, all 10 teams and most of the major players involved in the ABA.  It’s the definitive history of the ABA told by those who lived and loved it.  It is a classic sports book that deserves its place on the list of the all time greats.

As a companion piece, I’d highly recommend the ESPN 30 for 30 documentary Free Spirits which interviews many of those who spoke to Pluto, as well as Pluto himself.  It focuses on the Spirit of St. Louis team who lasted only two years, had a crazy cast of characters and whose owners secured the best financial deal in sports history when being denied a place in the NBA.


‘Sex, Lies, and Headlocks: The Real Story of Vince McMahon and World Wrestling Entertainment’ by Shaun Assael and Mike Mooneyham (2004)

I loved WWF (as it then was) as a kid, staying up all night to watch the Royal Rumble, refusing to fully accept it was scripted and staging highly dangerous wrestling matches with friends.  I don’t think I’ve seen 5 minutes of wrestling in the last 10 years or more.

When starting this blog I started hunting for books on sports stories I wanted to know more about.  Near the top of the search list was a biography of Vince McMahon, the legendary owner of World Wresting Entertainment.  The one book I could find that promised to cover McMahon’s life in any detail was Sex, Lies, and Headlocks from 2004.  I’ve enjoyed (and reviewed here and here) Assael’s other books and was looking forward to this trip down nostalgia lane.

Sex, Lies, and Headlocks gives a historical overview of the business of wrestling.  It’s very much about the business – the tv deals, the corporate takeovers, the court cases.  At its heart it’s the story of how wrestling became a billion dollar commodity.  A big focus is put on the various television networks and the role they played in the development of wrestling.  I have to admit, I would’ve enjoyed a bit more focus on some of the wrestlers personal stories.

The book also serves as a biography of Vince McMahon.  It covers his expansion of WWF after buying out his father, the controversy around steroids and sexual assault allegations and, in particular, the Monday Night Wars between WWF and rival WCW to be the dominant wrestling brand in the USA.

It is not a flattering portrayal of McMahon.  It’s clear that the McMahon family did not engage with the authors and it’s likely that those who were willing to speak were among the many who bore grudges against Vince.

Vince McMahon is a fascinating character.  He clearly has a keen sense of what sells and an absolute willingness to cross any boundary necessary to ensure his business is successful.  I always thought his decision to insert himself as the bad guy character in the show was utter genius – the blending of fact and fiction helping fans willfully suspend their disbelief and buy fully into the story-lines.  There are plenty of frankly bizarre anecdotes in the book which paint a picture of a slightly unhinged man with a genius for marketing and a love of risk taking.

There’s a good section on the XFL and McMahon’s ultimately doomed attempt to launch his own American Football league.  It’s particularly interesting given that XFL is now due to return in 2020.  I’m very interested in how XFL version 2 will fare, especially having recently read Jeff Pearlman’s excellent ‘Football for a Buck: The Crazy Rise and Crazier Demise of the USFL’ which captures the challenges and possibilities of a spring football league.

The book is definitely aimed at readers who may have been casual wrestling fans rather than at hardcore fans who will be well familiar with the stories told in the book.

I enjoyed the book a lot.  It’s well written, interesting and entertaining.  Vince McMahon is a fascinating character and I’d love to read a book updating on what has happened in the last 15 years!


(I can’t write about Vince McMahon with expressing my childhood frustration with how the name McMahon is pronounced in the USA – it’s an Irish name and in the Irish pronunciation the H is not silent. –  it’s pronounced with three syllables- MAC-MA-HON, not MAC-MANN)



‘Betaball: How Silicon Valley and Science Built One of the Greatest Basketball Teams in History’ by Erik Malinowski (2018)

As a kid, Channel 4’s decision in 1995 to start showing the NBA led me to fall in love with the sport of basketball.   The Bulls of Jordan’s second stint were the dominant team with Shaq led Orlando Magic also a particular favourite. Its only in recent years that I have rekindled a keen interest in the sport and got properly interested again after getting to watch Team USA play live at the Rio Olympics.  This season Sky Sports have bought the rights to show NBA games in Ireland so I finally have regular access to games again (and highlight shows at more Irish timezone friendly hours).

All of which means I kinda missed the rise of the Golden State Warriors – all of a sudden they were not just a new Championship contender, but a contender for the best team of all time.   I was really excited to read Betaball and figure out just how this happened.

Betaball is a very enjoyable read.  It’s a detailed retelling of the rise of the Warriors under its current ownership and the key personnel decisions that led to the creation of an elite team.  It’s also a pretty detailed blow-by-blow account of the key matches of the 14/15 and 15/16 seasons.

The book however promised more with its subheading of ‘How Silicon Valley and Science Built One of the Greatest Basketball Teams in History’.   The book talks about the use of analytics, the reliance placed on unconventional hires and the importance of a harmonious working environment it.  While there is a lot of talk about collecting and using data there really isn’t much insight into how or why their use analytics helped them win.  There are suggestions that the Warriors were better at focusing at rest and conditioning than other teams may have been but the thread isn’t fully drawn out in the book.

In many ways the story feels quite conventional – a new owner arrives and makes some really good personnel decisions, the unrealised potential of an existing player (Steph Curry) is finally realised, some really good draft picks (including a bit of luck in Green turning out better than anyone expected) are made and free agency is used wisely to secure the final missing pieces.

The book does give some interesting insights into the managerial and organisational culture introduced by the new owners.  In particular it was interesting how the new owners waited a full season before making radical changes.  It’s rare to see a sports team owner show such patience and not immediately try to remodel the team in their own image.  The process for decision making seems to have been very collegiate with everyone seemingly willing to listen to all viewpoints before making key decisions.

I don’t mean to be overly negative.  If the book was subtitled differently this would be a more positive review about how interesting the book was, the keen insight it gives into Steve Kerr in particular, and the interesting ways in which small changes can have a big impact on an team’s performance.

Overall, Betaball is a very interesting look at the rise of the Warriors, but not quite the book its subtitle promises it would be.