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.

Juventus bumped by Atalanta at the death

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Juventus is still in firm control of the Serie A title race, but they were dealt a slight setback as Atalanta secured a 2-2 draw with a dramatic 89th minute equalizer in Bergamo.

Dani Alves had given Juventus the lead in the 83rd minute on a header after a brilliant far-post cross by Miralem Pjanic, but Remo Freuler answered late as he grabbed a point.

The goal came on a fortunate bounce as Pjanic and substitute Stephen Lichtensteiner got tangled up on the ball and failed to clear, and the ball squirted to Freuler who suddenly found himself free in front of Gianluigi Buffon. The Juventus keeper came off his line to smother the chance, but he failed to completely collect, and the ball again popped free. Freuler followed up the loose ball, and with a trio of Juventus defenders flying in, the 25-year-old Swiss attacker knocked it in.

The draw was deserving for Atalanta, who had controlled the game for much of the first half, and went ahead just seconds before the break on a goal by Andrea Conti. Atalanta outshot Juventus 7-4 in the first half, 3-1 on shots on target. Juventus took over control in the second half, and got back on level terms just five minutes after the break as Juventus loanee Leonardo Spinazzola put one in his own net.

Alves’ goal put Juventus in front, but that lead only lasted six minutes. Juventus goes nine points clear at the top of the Serie A table with the draw, but Roma has the chance to cut that to six if they can beat Lazio at home on Sunday.

MLS Week 8: Litmus tests across the board

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Week 8 in MLS action could teach fans a lot about clubs with plenty to prove.

With questions still abound regarding teams like NYCFC, New England, Seattle, Portland, and New York Red Bulls, all those teams have a chance to make statements regarding their potential strength this season.

[ MORE: Week 8 MLS Power Rankings ]

In addition, struggling teams such as Los Angeles, Minnesota, and Montreal all have opportunities for much-needed points against arguably weaker opposition.

Let’s take a look at the weekend slate chronologically:

Toronto FC vs. Houston Dynamo
7:30 p.m. ET Friday

Toronto got a pair from Giovinco last time out, and sitting near the bottom of the crowded East mid-tier, they need points fast to avoid finding themselves in a hole behind the top of the table. There’s goals in this one, with Houston defensively challenged and Cubo Torres on fire to start the year.

Montreal Impact vs. Vancouver Whitecaps
3:00 p.m. ET Saturday

An all-Canadian clash actually serves as a vitally important match for both clubs. With each side near the bottom of their conference standings, they both need a result badly to jump-start the campaign. A draw does nobody any good here moving forward.

Orlando City vs. Colorado Rapids
4:00 p.m. ET Saturday

The Lions are one of 2017’s surprises, and Cyle Larin is on an absolute tear. Unfortunately, so far, anyone who shuts down Larin shuts down Orlando City. That said, good luck to Colorado shutting down an early MLS Golden Boot challenger.

Cyle Larin has 6 goals in 6 games this season (Photo by Alex Menendez/Getty Images).

NY Red Bulls vs. Chicago Fire
7:30 p.m. ET Saturday

New York has seen bumps on the early-season road, but overall remains a strong Supporter’s Shield contender. They face a big test against another strong Eastern Conference side, and a win here would make it three straight, all over good competition. Chicago is reeling after its defeat to Toronto, out-shot 9-1, but has another chance to pick up a road win before heading back home.

Columbus Crew vs. NYCFC
7:30 p.m. ET Saturday

Columbus has been poor on the road, but they return home to Mapfre Stadium to take on a strong NYCFC side. This game could potentially teach us a lot about whoever comes out on top, as both look to build separation from the rest of the pack in the East. Both have lost two of three, but both still appear strong up front, and three points in this game could prove to be a marquee win to point to later in the season.

Minnesota United vs. San Jose Earthquakes
8:00 p.m. ET Saturday

Minnesota United, owners of one of the worst starts to the season, has shown signs of life. Can they keep it going against another team struggling for points?

FC Dallas vs. Portland Timbers
8:00 p.m. ET Saturday

This is a marquee matchup, and with FC Dallas unbeaten so far, represents a huge test but also a huge opportunity for Portland to announce itself as a true top contender in the West. They’re top of the table, but have played at least one more game than most teams just below them. Can the Timbers find a way through the strong Dallas D?

Sporting KC vs. Real Salt Lake
8:30 p.m. ET Saturday

A big rivalry game with big table implications, Sporting KC has the unfortunate luck of catching RSL after hiring Mike Petke and not before. This should be a fun one.

Seattle Sounders vs. New England Revolution
10:00 p.m. ET Saturday

We still don’t know exactly what New England is. For every step forward they’ve taken one back, and for every setback they’ve had they’ve found a way through. This is a fantastic test. There are plenty of excuses for a potential loss with the team going cross-country to face one of the league’s best attacks, but a result could be a true statement.

LA Galaxy vs. Philadelphia Union
10:30 p.m. ET Saturday

With Philadelphia struggling and now traveling a long way, this should be a chance for the Galaxy to turn things around. Should be.

Atlanta United vs. D.C. United
3:00 p.m. ET Sunday

Atlanta is back home for the first time in over a month. They have slipped a bit since the torrid start, but still appear a dangerous club. D.C. will have its work cut out.

Asian FIFA executive pleads guilty to bribery charges

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A guilty plea was entered early Friday by senior Asian Federation (AFC) official Richard Lai to bribery charges, leading FIFA to suspend the 55-year-old indefinitely.

Lai has served as the head of the Guam FA since 2001, and is a member of the FIFA audit and compliance committee. He was also formerly a member of the AFC executive committee, and currently sits on the AFC marketing committee. Lai is a United States citizen.

The guilty plea confirms more than $1 million in bribes accepted by Lai, including those from Kuwaiti officials looking to increase their influence over FIFA voters in the confederation. Two unnamed AFC executives, including one Kuwaiti, were also named as co-conspirators.

“One of the functions the defendant Richard Lai performed for Co-Conspirator #2 and Co-Conspirator #3 in exchange for the funds they sent him was to advise them on who was supporting which candidates in AFC and FIFA matters, including elections, and who Co-Conspirator #2 and Co-Conspirator #3 should recruit to support their chosen candidates,” a Department of Justice document published on Friday said.

That wording seems to indirectly implicate Qatari executive Mohamed bin Hammam, who was banned for life by FIFA in 2011 for bribery.

“I would like to thank the American authorities for their continued efforts to stamp out corruption from football,” FIFA president Gianni Infantino said in a statement following the plea. “I am happy to confirm once again, that FIFA will provide whatever assistance is needed by the U.S. and any other authorities around the world.”

Lai has also been provisionally suspended by the AFC.

Argentina closes in on Sampaoli, according to FA boss

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The Argentinian FA is hoping to convince Jorge Sampaoli to abandon Sevilla and take the opening in his home nation.

President Claudio Tapia confirmed that Sampaoli is their top target, calling the 57-year-old their “chosen one” in an interview with ESPN.

“We have chosen a coach that has a contract,” Tapia told ESPN. “We want to be respectful and wait because he has a release clause which is once the tournament ends. We will communicate it to the club and we will sit down and negotiate his departure and release clause. We want things to go well in the final games he has left.”

Argentina dismissed coach Edgardo Bauza after the country fell to fifth in CONMEBOL World Cup qualification following defeats to Paraguay, Brazil, and Chile over the past six months.

Sampaoli is under contract with Sevilla until the summer of 2018, but has a $1.6 million release clause, to which Tapia was referring. Sevilla sits in fourth position in the La Liga table, level on points with Atletico Madrid but behind significantly on goal differential. The club finishes its league season on May 21st against Osasuna, and Argentina’s next game is a friendly on June 9th at home against Brazil. The next World Cup qualifier is in August against Uruguay.

Samapoli has been with Sevilla since since last summer in his first European club job, but the Argentinian has ample experience to take over for his home country. He managed Chile for four years, winning the 2015 Copa America in Chile. He resigned in early 2016 due to a contract dispute, paying a heavy price to do so as he gave up bonuses to wriggle free of his contract.

Argentina’s desire to secure Sampaoli as coach is nothing new, as the man himself confirmed an offer for the job a week ago, but said he would not consider it until the end of the season. It appears now that a deal is likely, and he will have a very short turnaround to get his first look at the team against a fierce continental rival.