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

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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.

MLS roundup: FCD, POR thrill in 2-2 draw; Sounders’ epic comeback

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With eight MLS Saturday afternoons/evenings officially in the books, only 26 more to go…

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FC Dallas 2-2 Portland Timbers

For the third straight week, we were a matchup featuring two of the top three teams in the Western Conference. After Sporting Kansas City beat Portland two weeks ago, and Dallas topped Sporting KC last week, it was FCD’s turn to host Portland on Saturday. Thankfully, the third game of the early-season round robin did not disappointed, and delivered a higher level of entertaining, attacking soccer (each of the first two ended 1-0).

Fanendo Adi opened the scoring to conclude a cagey opening 30 minutes, and out the window went all semblance of structure and discipline from either side. FCD needed a full 30 minutes before they’d draw level, courtesy of Maximiliano Urruti, a goal that set up a fantastic, frantic final half-hour.

Sebastian Blacno’s first MLS goal put Portland ahead for the second time in the game, in the 71st minute, but the advantage was short-lived, as Tesho Akindele’s 80th-minute header brought FCD back to level terms once again.


Seattle Sounders 3-3 New England Revolution

Game. Of. The. Day.

Seattle found themselves 3-0 down to New England, at home, after 54 minutes. In 13 minutes’ time, from minute 75 to 88, the comeback was on. There’s not much to be said of this one. Just sit back, and enjoy.


Orlando City SC 2-0 Colorado Rapids

Five home games, five wins for Orlando City. The best home-field advantage in all of MLS might just reside in central Florida, and the summer humidity is yet to reach full effect.

Saturday’s victory over a truly awful Rapids side was more labored than you might have expected — all of 70 minutes passed before Carlos Rivas scored the breakthrough — but the result was never in doubt. Colorado managed all of three shots (one on target) over the course of 90 minutes, and Kaka marked his return to action (hamstring injury) with a goal in the 91st minute. All is very, very well in the City Beautiful.


New York Red Bulls 2-1 Chicago Fire

Dax McCarty’s return to Red Bull Arena, following the trade that sent him to Chicago during the offseason, was more than a little bittersweet for the box-to-box bulldog when spent five and a half seasons with New York.

After falling behind to Bradley Wright-Phillips’ opener in the 37th minute, McCarty assisted on Nemanja Nikolic’s 59th-minute equalizer — the spin and lay-off were perfectly executed. The evening ended in disappointment, though, as Kemar Lawrence broke the deadlock in the 71st minute and secured all three points. That’s back-to-back losses for Chicago, who were unbeaten in their first three games since Bastian Schweinsteiger‘s arrival. On the other end, three straight wins for New York, and they’re within two points of first-place Orlando in the Eastern Conference.


Columbus Crew SC 2-3 New York City FC

When two teams with zero desire to play the game at a non-frenetic pace, and no clue how to slow things down and control the game, get together, fireworks are to be expected.

Columbus and New York City meet the above criteria, and were happy to prove as much on Saturday. Jack Harrison put the visitors ahead with the deftest chip in the 8th minute, but Federico Higuain’s equalizer 21 minutes later was just as impressive.

Ola Kamara put Columbus 2-1 ahead in the 49th minute, and all Gregg Berhalter’s side seemed to be in total control. 15 minutes, later Angel Herrera’s header made it 2-2, and Jack Harrison completed the comeback in the 76th minute. Few victories in MLS this season will deserve greater praise than this one, achieved without the services of David Villa (illness).


Sporting Kansas City 3-0 Real Salt Lake

When Sporting KC get themselves a lead, it’s game over. In the four games in which they’ve scored this season, they’ve won 12 out of 12 points possible. On the season, they’ve conceded three goals in eight games, and haven’t conceded multiple goals in a game yet this season.

Of course, scoring has been the majority of the problem, as Peter Vermes’ side has already been blanked four times themselves. It wasn’t a problem on Saturday, though, as Benny Feilhaber, Dom Dwyer and Gerso Fernandes were each stellar from beginning to end, and each bagged a goal in Sporting’s 3-0 win over RSL. An inability close out games has haunted this team in the past, but they’re a perfect 4-for-4 thus far in 2017.


Montreal Impact 1-2 Vancouver Whitecaps

Someone’s giving Colorado a run for their money as the worst team in MLS. With just a single win to their name this season, Montreal have to make the most out of 1) home games; 2) games in which they lead, if they’re to mount any kind of playoff challenge in 2017.

They did neither against Vancouver, throwing away an early 1-0 lead — Marco Donadel opened the scoring in the 9th minute — by conceding goals either side of halftime, to Andrew Jacobson and Cristian Techera. In truth, Vancouver were the better side over 90 minutes and fully deserved the three points, and it’s a crushing result for a Montreal side with just one victory (and zero clean sheets) on the season.


Minnesota United 0-1 San Jose Earthquakes

Elsewhere in MLS

LA Galaxy 0-0 Philadelphia Union

Ligue 1: Level on games played, Monaco go 3 points ahead of PSG

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PARIS (AP) Monaco warmed up for its Champions League semifinal against Juventus with a 3-1 win over Toulouse to move three points clear of Paris Saint-Germain at the top of the French league on Saturday.

Teenage striker Kylian Mbappe, the new wonder of French football, scored his 14th league goal this season.

Kamil Glik and Thomas Lemar also got on the scoresheet for the hosts.

Mbappe has been unstoppable in recent months, scoring 22 goals in his last 20 starts in all competitions.

Having turned 18 just four months ago, Mbappe has scored 24 goals in 38 games in his first full professional season to become one of the most sought-after players across Europe.

Both Monaco and PSG, which travels to third-placed Nice on Sunday, have four league matches left to play.

After rotating his team in a 5-0 loss to PSG in the French Cup to save his best players for Wednesday’s Champions League clash, Monaco coach Leonardo Jardim switched back to his usual starting lineup. His players made a slow start but ended up scoring three goals – their average this season.

Toulouse, which upset Monaco 3-1 in the corresponding fixture last October, had the first chance in the 10th minute when the unmarked Andy Delort sent a header inches wide at the far post from a free kick.

Monaco gradually worked its way into the game and took a firm grip near the half-hour. Following a one-two with Thomas Lemar, Bernardo Silva dribbled past a defender and forced `keeper Alban Lafont to make a good save to his left.

The youngest player in French league history to reach 10 goals in a season, Mbappe was then perfectly set up by Nabil Dirar’s long ball down the left flank but saw his effort deflected by a last-minute tackle from Toulouse skipper Issa Diop.

Struggling to break a well-organized defense, Monaco kept peppering the box with teasing crosses but lacked a cutting edge.

Monaco found itself trailing against the run of the play just after the interval following a blunder from Jemerson. The Brazilian defender fluffed the ball in front of goal, allowing Ola Toivonen to beat Danijel Subasic with a clean finish.

The goal spurred Monaco on even more and Glik put the teams level with a beautiful header into the top right corner from Joao Moutinho’s cross.

Mbappe made it 2-1 in the 64th minute after Bernardo Silva set him up on the right side of the area, rifling a shot into the net from a tight angle.

Lemar completed the win in the 75th minute from Dirar’s clinical cross.

New York Red Bulls introduce space at RBA for autistic families

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HARRISON, N.J. (AP) The Red Bulls have announced plans for a permanent sensory-friendly space at their stadium for families impacted by autism.

Formerly executive offices, the space overlooking midfield is a calm area that is free from the crowds and the noise of Red Bull Arena during matches. Families can use it for free.

The team announced the new space on Saturday before the Red Bulls were set to host the Chicago Fire. It was Autism Awareness Night at the stadium.

“Families deserve to feel welcome and comfortable each time they step foot into Red Bull Arena, not just one night a year,” Red Bulls GM Marc de Grandpre said in a statement released by the club. “We hope all sports teams and entertainment venues are inspired to take similar action to provide comfort for families with loved ones on the autism spectrum.”

League Two game restarted in empty stadium after fans storm field

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LONDON (AP) An English soccer game restarted in an empty stadium after a pitch invasion led to the crowd being told the fixture had been abandoned.

There were five minutes remaining in Leyton Orient’s fourth-tier game against Colchester on Saturday when a sit-down protest was staged on the pitch by Orient fans against Italian owner Francesco Becchetti.

It forced the referee to take the players off the field. The protests lasted for more than an hour before the crowd was told the game had been abandoned and the stadium eventually cleared. The teams came out and finished the game.

Leyton Orient lost 3-1 a week after its relegation from the English Football League was confirmed after 112 years.

“A decision was taken with the police to announce that the game had been abandoned as it was felt this would help clear the pitch, which proved correct,” the EFL said in a statement. “However, it was deemed appropriate that the game needed to be played to a conclusion in order to maintain the integrity of the competition.”