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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.

3 things we learned from the USMNT win over Canada

PORT OF SPAIN, TRINIDAD & TOBAGO - NOVEMBER 17: Jermaine Jones #13 keeps the ball in play during a World Cup Qualifier between Trinidad and Tobago and USA as part of the FIFA World Cup Qualifiers for Russia 2018 at Hasely Crawford Stadium on November 17, 2015 in Port of Spain, Trinidad & Tobago. (Photo by Ashley Allen Getty Images)
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The United States played to a disjointed and sloppy win over Canada to wrap up January camp. It was promising at times, but mostly a cringe-worth display by both sides. Here are the key notes from the 90 minutes at StubHub Center in California.

1) Jermaine Jones should never play CB again

Look, this probably wasn’t ever the plan, and it probably never is. It’s the “break glass in case of emergency” option. With Matt Miazga likely supposed to start one or both these games before he left for Chelsea, and the departure of Michael Orozco and Brad Evans, the U.S. was thin at the back.

Still. Yikes…

Jones was flat out awful. Just days after he played well in a midfield distribution position against Iceland, he was a total mess at the back. Jones was miserable on the ball, giving it away with ugly touches, he lunged in on challenges including one on Cyle Larin early that very well could have resulted in a Canadian penalty. And he charged forward – something a central defender can never do – leaving his teammates caught out at the back. This ended with Matt Besler getting a yellow card:

Please, Jurgen. Never again.

2) Jordan Morris is developing into a useful player

In his first cap since signing a professional contract with the Seattle Sounders, Morris gave his critics much to think on. Many said the 21-year-old would come and go without much staying power, but he partnered well with Jozy Altidore. There wasn’t much service up front during his time on the field, but when there was, Morris drew defenders off Altidore, and he provided a solid foil to his bigger partner with his speed and precision. He didn’t have many opportunities, but when he did, he made his presence known.

3) Playing players out of position very rarely bears fruit

Soccer coaches often have two choices at their disposal when building a lineup: either pick the best 11 players and position them into a formation that fits their skills best, or pick a formation and then select the 11 players that fit that formation the best. Klinsmann prefers neither. Instead, recently he’s been picking 11 players he wishes to play, choose a formation he feels will fit the opponent, and then tries to force the players he chose into the formation he selected.

It hasn’t worked, especially not today. He tried to force 3 center-backs onto the back line. He tried to force three central midfielders (and Zardes) into a flat four midfield that occasionally looked like a flat diamond. Neither worked. It’s an experimental environment, sure, but the benefits of his choices aren’t entirely clear.

We know what doesn’t work, but we still don’t really know what works, and isn’t the latter what January camp was for?

4) Jozy Altidore needs to work on his heading…oh

Bonus! So, as the game wound down, I had written that Jozy needed to work on his heading in front of net. The 26-year-old had a few headed opportunities in the box throughout the game, and he failed to capitalize. He looked to drill it into the ground on multiple occasions, but from the distance most of his efforts came from, he likely should have looked to aim his headed shots rather than use the ground pound technique.

Then, you know, he scored the late winner on a header. So, yeah. Never mind. But still. Yeah. Whatever.

United States 1-0 Canada: Altidore snatches late winner in sloppy meeting

CARSON, CA - FEBRUARY 5: Jozy Altidore #17 of the United States battles with Steven Vitoria #15 of Canada during the first half of their international friendly soccer match at StubHub Center February 5, 2016 in Carson, California. (Photo by Kevork Djansezian/Getty Images)
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It was sloppy. It was sleepy. It was cringe-worthy at times. By the final whistle, Jozy Altidore refused to let it end goalless.

January USMNT camp wrapped up with an erratic, disjointed but successful 1-0 win over their northern neighbors as Jozy Altidore bagged a headed winner in the 89th minute.

U.S. head coach Jurgen Klinsmann chose to start a number of players out of position, including a trio of central defenders along the back line and an odd midfield combination that sat back for much of the game. Jozy Altidore and Jordan Morris partnered up front, and worked well with the sparse service they received.

Both back lines looked relatively shaky to start, and each midfield was sloppy under heavy pressure from the opposition. The first true chance came on 15 minutes as a beautiful touch with the outside of Gyasi Zardes’s foot found a cutting Jozy Altidore, and the forward’s shot beat Maxime Crepeau but crashed into the post. The ball then rebounded into the back of Crepeau and back off the post a second time before the Canadian goalkeeper finally collected.

Four minutes later, Canada had a penalty shout as Jermaine Jones lunged into the back of Cyle Larin who was attempting a volley from the top edge of the box, but the referee waved it off.

As those chances faded, the game became a snoozer and the U.S. attack devolved into long balls lumped forward. Jones was miserable at the back, looking completely out of position. Both Michael Bradley and Mix Diskerud sat back in possession, leaving Lee Nguyen and Gyasi Zardes isolated up front with no wide threat.

The U.S. had another spell of attack before halftime. Altidore sprung Jordan Morris on the left edge of the box, but his chipped effort skittered just wide. Bradley tried a left-footed effort on net on 39 minutes, but his shot was easily saved low by Crepeau. Matt Besler earned a yellow card by clipping the heel of Larin just before the break, forced into the foul after Jones was caught out of position.

Thankfully, the first half ended. Klinsmann made one halftime change, bringing on Brandon Vincent for his first USMNT appearance in place of Kellyn Acosta, whom the manager said had a hamstring problem. The U.S. pushed forward early, and they had a 53rd minute chance when Diskerud lofted a ball to the far post where Altidore met it with his head, but he pushed an effort on goal just wide left, inches out of reach by Morris.

Things settled until the 66th minute, when substitute Jerome Kiesewetter found Altidore in the box, but he drove it into the ground meekly. In the 70th minute some U.S. pressure bought a shot for Vincent, but it was saved well by Crepeau’s feet. Altidore had another big chance with six minutes to go, and he went for the off-balance chip that aged as it traveled through the air, slow enough to allow Crepeau to recover and slap it out of danger.

Klinsmann brought Morris off with just three minutes to go in regulation, bringing on Steve Finlay, who had an instant impact. Finlay cut inside from the left and lofted a ball to the far post, one which Altidore lept to meet, finally finding the back of the net after having bungled a few earlier headed opportunities.

The win leaves the United States 2-0 in January camp, and despite a few clear deficiencies, the end results were there.

USMNT lineup vs Canada sees Jermaine Jones at CB, Morris and Altidore up front

at StubHub Center on January 31, 2016 in Carson, California.
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The United States takes on Canada for the second of two friendlies that test those involved in January camp. With Iceland already dispatched 3-2, Canada is next up, at 10:30 p.m. ET from the StubHub center in California.

Jurgen Klinsmann has chosen his lineup, and it’s not easily discernible.

[ MORE: Full preview United States vs Canada ]

The back line is the biggest head-scratcher, with three central defenders starting, and at least one of them out of position. Jermaine Jones, who performed well in a midfield distribution role against Iceland, has been moved back to the defensive line, partnering with Matt Besler. Steve Birnbaum, also a central defender who had ups and down against Iceland, is back in the lineup. There’s nowhere to fit a third central defender, so he will play out wide. Kellyn Acosta, a natural full-back, rounds out the back four.

In midfield, the personnel lends itself to a flat four, if only because there’s really no other way it can go. Again, a multitude of central defenders are deployed, with Michael Bradley, Lee Nguyen, and Mix Diskerud forming some kind of CM/CM/Winger combination (Nguyen is likely the odd man out wide), with Gyasi Zardes out wide on the other end.

[ MORE: 3 key battles for USMNT vs Canada ]

Jozy Altidore returns up front, this time to partner with Jordan Morris, who makes his first USMNT appearance as a professional player.

Finally, San Jose Earthquakes goalkeeper David Bingham makes his USMNT debut between the sticks.

Jurgen Klopp says Daniel Sturridge is focused on getting healthy, not leaving Liverpool

during the Capital One Cup quarter final match between Southampton and Liverpool at St Mary's Stadium on December 2, 2015 in Southampton, England.
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Jurgen Klopp has made his frustrations with Daniel Sturridge‘s injury history very clear, but he still knows the England international is a crucial part of his squad, and he will be patient, no matter how frustrating it is.

Sturridge has been out since early December, and has made just five appearances all season due to a number of recurring injuries that have sapped him of his consistency for the last two years.

But with the 26-year-old back in training the last two days, the English media has speculated that Sturridge is looking to leave Liverpool, and that the club is trying to rid themselves of him as well. Klopp does not see it that way.

[ RELATED: Daniel Sturridge says he’s “good to go” ]

“I have no feeling that Daniel is thinking like this so stop thinking about it,” Klopp said in his pre-match press conference, speaking ahead of the match Saturday against Sunderland. “I spoke to him but not about this. I didn’t ask: ‘do you want to leave?’ “Why should I? He’s been back in training for two days. I don’t go over and say: ‘Daniel, I hear you want to leave? Is there truth in it?’ I don’t believe that it is like this.”

Klopp called the rumors a “non-story” and believes as soon as Sturridge is out on the field, the rumors will stop. He just has to get out on the field first.

“Since I was here I’ve had a normal relationship with Daniel Sturridge,” Klopp said. “The only problem is I have only had him 10 or 12 times on the training pitch – that is the truth. Now he is back we hope he can stay in team training and everything will be good. If everything is normal from now on then he is in the race.”

The German said that just having returned to training, Sturridge won’t be ready for Saturday’s game, but he could potentially be back to action for the FA Cup match against West Ham on Tuesday.