Barcelona's midfielder Xavi Hernandez re

Compromised numbers: Why the statistic you see may not be actual possession


One of the amazing statistics to come out of last Wednesday’s UEFA Champions League match was the possession number. Barcelona was reported by UEFA was having held the ball 72 percent of the time, an amazing figure against a club of Chelsea’s caliber. For those who have tried to find significance to correlations between possession and victories, the number must have been both remarkable and beguiling. After all, Barcelona lost, giving more credence to the hypothesis’ main qualm: What if one team doesn’t care about holding the ball?

The next day, the possession story got even more confusing. Supreme stat overlords Opta reported that Chelsea had only managed 20 percent of the ball. What? Even less time in possession? How freakish is this data point going to get?

That, however, is not the story. At least, it’s the story in light of what Graham MacAree notes at Chelsea fan site We Ain’t Got No History. As he’s found out, Opta seems to be miscalculating possession; or, better put, Opta is not reporting a number consistent with the normal expectation for a possession stat.

The normal expectation: When one team has the ball, they’re in possession. I think we can all agree on this, right? This still leaves a lot of gray area. For example, who gets credit for possession when midfield chaos leaves neither side in control? Does one team get possession on a goal kick, when most goal kicks lead to 50-50 midfield challenges? And more broadly, what happens when play is dead but the game clock is running?

I’ve always assumed this is like a chess clock. When one team controls the ball, you hit a button that sends their dials turning. When the other fully regains possession, you hit a button. One clock stops. The other starts running. Those in between moments? They’re governed by one rule: Until possession changes, don’t touch anything.

That, apparently has nothing to do with Opta’s calculations. In fact, Graham’s research suggests Opta doesn’t even run a clock, which may be why they never report possession in terms of time. Instead, the relation between reported possession and total passes suggests Opta just uses passes. As Graham found out, if you take a team’s pass attempts a divide it by the game’s total attempted passes, you have Opta’s possession stat.

What does this mean? Let’s take a totally fake scenario. Barcelona plays three quick passes before trying a through ball that rolls to Petr Cech. It all takes four seconds, while Petr Cech keeps the ball at his feet for eight seconds before picking it up, holding it for five seconds, then putting it out for a throw in, which takes eight more seconds to put back into play.

Despite Barcelona having possession for only four of those 25 fake seconds, they’d have 80 percent of Opta’s possession (three good passes plus one bad, while Chelsea had only Cech’s unsuccessful pass). A logical expectation of a zero-sum possession figure would have that as either 16 percent or (if you credit the time out of play as Barça’s, since they’d have the ensuing throw) 48 percent Barcelona’s. Or, if you do a three-stage model (that’s sometimes reported in Serie A matches), you’d have 16 percent Barcelona, 52 percent Chelsea, and 32 percent limbo/irrelevant.

Of the three methods of reporting possession, Opta’s bares the least resemblance to reality; or, it’s the one that deviates furthest from what we expect from a possession stat.

Ironies being a thing these days, there are two here. First, Opta is the unquestioned leader in soccer data management. How could this happen?

Second, Opta isn’t trying to hide their methods. In fact, they’ve published a post on their site detailing not only their practices but their motivations and research, an investigation that found their approach “came up with exactly the same figures (as time-based methods) on almost every occasion.”

You would think two curmudgeons like Graham and myself would have found this, right? Graham had a reader point it out to him, while a representative from Opta magnanimously pointed me to the piece without the seemingly necessarily indignation of explaining how a Google search works. After all Graham’s work and head scratching – after my lack of work and similar head-scratching – we could have just gone to Opta’s site.

“We try to be as transparent as possible with this stuff,” Opta said when I asked them about it. Certainly, they should be commended being so up front about their methods. After all, they’re a business that makes money off their work. They don’t need to give away their secrets.

But that’s a secondary issue. The main one: Why is a data house like Opta, reputed as the industry standard, taking this short cut? Or, why haven’t they renamed their measure? Granted, the perception that it is a shortcut may have more to do with our expectations than their intent, though based on their defense in the post, it’s clear they do see this as an accurate way of describing possession.

Still, the number they publish is completely redundant to the raw passing numbers also distributed. Why put the measure out at all if not to check a “possession stat” box on a list of deliverables?

Opta’s possession stat shouldn’t be cited in reporting, and if it is, the word “possession” shouldn’t be used to describe it. Reader expectations for anything labeled “possession” are drastically different than what Opta’s producing. The number is confusing to the point of being misleading. It’s becoming counter-information because of its poor packaging.

Even though Opta’s post on the topic is 14 months old, most will be surprised to hear this “news.” It’s disconcerting for anybody who is hoping a SABR-esque revolution’s on the horizon. Almost all of the huge volume of data to which we have access has been useful, but where people are expecting something akin to linear weights to be published tomorrow, we can’t even agree on the terms (let alone the significance of them).

Graham probably puts it better:

I’m completely fine with keeping track of passing volume – I’ve done it before myself. What’s frustrating, from an analyst’s point of view, is that we’re being sold a dud. A statistic that ostensibly measures possession measures something that is not possession, and gets repeated as authoritative anyway.

And people wonder why football statistics don’t get taken very seriously.

Klopp’s blockbuster arrival brings hope back to Liverpool

LIVERPOOL, ENGLAND - OCTOBER 09:  Jurgen Klopp is unveiled as the new manager of Liverpool FC during a press conference at Anfield on October 9, 2015 in Liverpool, England.  (Photo by Alex Livesey/Getty Images)
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LIVERPOOL – Jurgen Klopp is box office in every sense of the word.

His relaxed demeanor makes him likable, yet he also exudes self-confidence, something he will need a lot of in the coming weeks and months as he tries to get Liverpool’s players to believe in his methodology and drag the illustrious club back to the top of the Premier League and get them challenging for trophies at home and in Europe.

[ MORE: Dazzling Anfield arrival ]

Klopp, 48, put on a dazzling show during his glitzy unveiling as Liverpool’s new boss on Friday at Anfield, declaring himself as the “Normal One” when asked of his comparison to Jose Mourinho, while he also revealed that he hopes to turn Liverpool “from doubters into believers” during his time in charge on Merseyside.

Being in the packed press conference in the Centenary Stand at Anfield on Friday, there was a palpable buzz and sense of excitement in the air as the British, German and world ‘s media descended on Anfield. The terraced rows of streets in and around Anfield were busier than usual. All roads led to Anfield. All roads led to Klopp. He didn’t disappoint as he delivered a flawless display of controlled optimism.

Previously he had described this opportunity to manage Liverpool as the “most interesting job in world football” at the moment. Everyone was interested in what he had to say, as he strode into the presser with a beaming smile on his face, wearing a a pair of jeans and a stylish unbuttoned shirt complemented with a trendy blazer. Make no mistake, signing Klopp to a three-year deal is a major coup for the Reds as any of Europe’s giants would have snapped him up had a managerial vacancy arisen over the past four months since he left Borussia Dortmund.

[ MORE: Klopp’s 10 best quotes

Friday marked the biggest managerial appointment for Liverpool in a decade, as all the stops were pulled out to make sure the German coach was given a royal welcome at Anfield, a pantheon of world soccer which he is eager to wake up from its trophyless slumber. After the presser, Klopp was ushered onto the pitch as he posed for pictures in front of the huge $165 million renovation of the Main Stand which will add over 7,000 corporate seats at Anfield and help the club generate extra revenue to compete with the four clubs currently above them — Arsenal, Chelsea, Manchester City and Manchester United — in the Premier League’s rich list. Liverpool’s American owners Fenway Sports Group (FSG) will be celebrating their fifth anniversary at the club next week. This appointment was one of their biggest moments, if not the biggest, to date under John W. Henry and Co.

Klopp has previously spoken about his ability to coach with feeling. On Friday he spoke with feeling, with humor and engaged the audience as mutterings such as “he’s enthralling, gripping, isn’t he?” could be heard among the press. His enthusiastic mannerisms on the sidelines and his ability to conjure fervor from fans and players has been well documented. He is a man who is at one with the working-class people who make up the vast majority of the local fanbases for his previous clubs Mainz and Dortmund, and now his new club, Liverpool. He seems tailor-made for this adventure at Anfield.

Jurgen Klopp at Anfield is unveiled as the new manager of Liverpool FC during a press conference at Anfield on October 9, 2015 in Liverpool, England.
Klopp engages with the press.

In the past three seasons, hope of success flickered brightly at first, then intermittently, before fading in recent months. Liverpool failed to win a single piece of silverware under Brendan Rodgers, with the Northern Irishman finally shown the exit door last Sunday. In Rodgers’ place stands a coach who has been here before.

At Dortmund Klopp rebuilt the team from relegation candidates to two-time Bundesliga champions in his seven years in charge. He led them to the UEFA Champions League final (where they lost narrowly to German rivals Bayern Munich at Wembley) and built a young squad who was hungry to succeed and bought into his methods of high-pressing early in games and pacey counters later.

The similarities between the situation Klopp now finds himself in at Liverpool are strikingly similar to the one he acquired at Dortmund when he arrived from Mainz in 2008.

“We did in Dortmund what we had to do, to improve the players, to work for a common idea of play. That is what we did and its the same thing we want to do here. They are not the same players of course,” Klopp told NBC Sports ProSocerTalk. “These players from Liverpool are better, more experienced in some ways and younger in other cases. Everything is okay, I am here. I am not here only because LFC was calling. I believe in the potential of this team. Four or five strikers you can work with when they are not injured, midfielders is really good, defenders experienced and very young, goalkeeper is really good. Everything is there.

“Now we have to work. The problem in football is that you can be as good as you want but you always have to play against other teams. You have no influence on how good they are before the game. But in the game, if they are better, you have to bring them to your level. On your level you can kill every team. If they are not so good, you have to win. That is football.”

A towering six-foot four-inch veteran of the 2. Bundesliga during his playing days, Klopp’s soccer brain has been revered and he takes his staff wherever he goes. Longtime allies Zeljko Buvac (who he nicknames ‘the brain’) and analyst Peter Krawietz have joined Klopp at Liverpool, as he aims to replicate the success he had at Dortmund. He also revealed he is comfortable with the transfer committee which many blamed for Rodgers’ downfall. “It’s enough for me to have the first and last word.”

Liverpool’s 25-year wait for a 19th league championship may not end anytime soon but under Klopp FSG have got the man they were after. As he mentioned when saying: “I am not here only because LFC was calling. I believe in the potential of this team,” Klopp has placed his managerial reputation on the line to try and stir a sleeping giant of English soccer with his raucous celebrations and infectious enthusiasm set to grace the touchline for at least the next three years at Liverpool. If this initial appearance before the press is anything to go by, Klopp will bring plenty of life to the PL.

He has become the second German to coach in the Premier League, after the short-stint of Felix Magath at Fulham almost two years ago, and Klopp’s English is very, very good as he engaged with the press and put on a flawless show of charisma, style and confidence.

“In Jurgen Klopp we have appointed a world-class manager with a proven track record of winning and someone who has the personality and charisma to reignite this football club and take the team forward,” Liverpool chairman Tom Werner said in a statement. “He possesses all the qualities we are looking for in a manager, he is a strong, inspirational leader, who has a clear philosophy of high energy, attacking football. Critically, he is also a winner and someone who can connect with and enthuse our supporters.”

The club. The fans. The players. Klopp blends it all together perfectly. He gets what a club like Liverpool means to the fans and now shares their hopes and dreams.

Perhaps one of the most poignant quotes to come from Klopp was that he wants his players to believe, not be downtrodden by, the huge expectation placed on them by the fans and the media worldwide.

“It is a really important thing that the players feel the difference from now on,” Klopp said. “They have to think they can reach the expectations of all the people, of all the fans, of the press. We have to change from doubters to believers. We have to change our performance, of course, but stop thinking about money. It is only about football.”

There was no football played on Friday as Klopp will get to work early next week when the majority of his squad arrive back at Melwood from international duty. But the talking he did on Friday, with charisma oozing from his comments in both English and German, impressed and proved he is relaxed and capable of delivering success to a club which has been crying out for it for a very long time.

Euro qualifying Friday preview: Lopsided scores in the offing?

Harry Kane, England
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Spain can book its place in France with a win over Luxembourg on Friday, just one of several match ups of giants and minnows on the docket.

The real Group C battle is for second in the group, as Ukraine should easily pick up three points against basement-dwelling Macedonia, which would keep its Top Two hopes alive should Slovakia drop unlikely points at home to Belarus.

Roy Hodgson has set England’s sights on an undefeated run through group play, and that could crush Estonia’s hopes in Group E. Sitting fourth, two points back of Slovenia, Estonia has a tough duo of matches to finish (Switzerland is next).

The Swiss, for their part, have No. 6 San Marino, while Slovenia can stay in they playoff driver seat with a win versus Lithuania.

Will Austria be on cruise control, given it’s won Group G in a landslide? Montenegro will hope so, but their hopes also hinge on Sweden and Russia picking up historic upset losses on the road.

Macedonia vs. Ukraine
Slovakia vs. Belarus
Spain vs. Luxembourg
England vs. Estonia
Slovenia vs. Lithuania
Switzerland vs. San Marino
Liechtenstein vs. Sweden
Moldova vs. Russia
Montenegro vs. Austria