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.

Juninho hoping Willian breaks his Champions League free-kick record

xxxx during the Barclays Premier League match between Chelsea and Southampton at Stamford Bridge on October 3, 2015 in London, United Kingdom.
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Willian has scored six goals for Chelsea this season, with all six coming from free kicks.

Four of those have been scored in the Champions League, as the Brazilian has tied the record for the most free-kick goals in a single UCL campaign.

[ MORE: Premier League roundup ]

Willian is tied with his fellow Brazilian Juninho, known as one of the deadliest set-piece takers of all-time, who scored four times for Lyon during the 2005-06 campaign.

When asked about the possibility of his record being broken, Juninho was glad it would be by another Brazilian player, and said Willian will likely surpass him in the coming matches.

It’s good it’s a Brazilian, and from this new generation of good players we have.

It is very gratifying for me because when I scored these four goals, no one said anything.

I’m being remembered by what Willian has achieved, and I think he has everything to beat the record. The Champions League has barely reached half way and Chelsea still have a few more games to play.

Willian has converted 6 of 12 free kicks this season, scoring at an unheard-of 50-percent clip. All of his goals have come from almost the exact same spot on the pitch, about 20-25 yards out at the corner of the box to the keepers right.

[ WATCH: Jamie Vardy scores in record 11th straight Premier League match ]

Chelsea’s next Champions League match is on December 9 at Stamford Bridge against Porto. The Blues need a draw to advance into the knockout round.

West Brom’s Jonas Olsson backs Zlatan for Premier League move

SOLNA, SWEDEN - NOVEMBER 14: Sweden 10 Zlatan Ibrahimovic durring a European Qualifier Play-Off between Sweden and Denmark on November 14, 2015 in Solna, Sweden.  (Photo by Michael Campanella/Getty Images)
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With his contract at Paris Saint-Germain expiring in the summer, where Zlatan will go next is one of the biggest mysteries in football.

Having already played in the Netherlands, Spain, Italy and France, the Premier League would be a logical next step in Zlatan’s career.

[ MORE: Aguero injury update ]

However, at 34-years-old, Zlatan himself has said it is “too late” for him to play in England, adding more mystery to where he will end up.

Despite what Zlatan says, his teammate on the Sweden national team Jonas Olsson believes the PSG striker is more than capable of playing in the Premier League.

Olsson, who has made nearly 400 appearances for West Bromwich Albion over the past eight seasons, said Zlatan’s elite talent would be fit for England’s top flight.

He’s still at the top of his game. He is the strongest player I have faced. I really hope he comes.

Zlatan on his day is the most talented footballer in the game. He has played under Mourinho before and the only place where he’s not 100% appreciated is in the UK.

I think he can play for any team in this league – he is still that good.

Even at 34, Zlatan has proven he is still one of the best strikers in the world. He recently became Paris Saint-Germain’s all-time leading scorer, and has scored at least 30 goals in each of the past four seasons.

[ VIDEO: Jamie Vardy speaks after scoring in 11 straight Premier League matches ]

The Premier League certainly has the money to entice Zlatan, and it is the biggest league in the world that he hasn’t conquered yet. Expect his name to be linked with a move to every major club in Europe for the rest of the year, as we’ll just have to wait until June and see what he decides.

Three questions ahead of Sunday’s MLS Conference Finals

PORTLAND, OR - NOVEMBER 22: Goal keeper Adam Kwarasey #12 of Portland Timbers slides in on Michael Barrios #21 of FC Dallas during the second half of the match at Providence Park on November 22, 2015 in Portland, Oregon. (Photo by Steve Dykes/Getty Images)
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There are only two matches remaining before MLS Cup, with both conference’s top seeds in need of a big result.

FC Dallas lost to the Portland Timbers 3-1 in the first leg out West, while the New York Red Bulls fell 2-0 to Columbus Crew SC in the East.

[ FOLLOW: All of PST’s MLS coverage ]

Leg 2 of the Conference Finals will both be played on Sunday, as we will know the MLS Cup finalists by the end of the night.

WEST: FC Dallas vs. Portland Timbers — 5 p.m. ET
EAST: New York Red Bulls vs. Columbus Crew SC — 7:30 p.m. ET

With each home-side needing to overcome a two-goal deficit, here’s what to look out for in the Conference Finals.

Will FC Dallas capitalize on home-field advantage?

Despite being down 3-1 on aggregate, FC Dallas will be looking forward to Sunday’s second leg. Dallas finished the season 13-2-2 at Toyota Stadium, the best home record in MLS. After scoring a crucial away goal in Portland, a 2-0 win for Dallas will see the side advance to the final. Their 33 goals scored at home was the second-best mark in the Western Conference, as Oscar Pareja’s men will feel confident despite the aggregate.

[ VIDEO: USMNT’s Fabian Johnson scores twice for Monchengladbach ]

Is Norberto Paparatto ready to replace Liam Ridgewell?

Norberto Paparatto has played just six matches for Portland this season, but it looks like he’ll be starting on Sunday. Liam Ridgewell, who started all 32 matches at center-back, injured his calf in the first leg and manager Caleb Porter said Paparatto will “most likely” be starting, as Ridgewell was seen warming up separately from the rest of the team in training. With FC Dallas in need of goals, Paparatto will have his hands full on defense, especially with the likes of Fabian Castillo and Mauro Diaz bombing forward.

Can Luis Robles keep a clean sheet for RBNY?

The Red Bulls’ Luis Robles was named MLS Goalkeeper of the Year this season, and he’s going to need to play like that on Sunday. After losing 2-0 in the first leg without scoring an away goal, New York needs a 2-0 win themselves just to force extra-time. If Columbus scores at Red Bull Arena, New York needs to score four goals to advance. While it will have to be a collective team effort to keep the Crew off the scoresheet, Robles will have to make some big saves in goal to keep his side in it.

La Liga roundup: Barcelona win big in another dominant performance

<> at Camp Nou on November 28, 2015 in Barcelona, Spain.
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Catch up on all of Saturday’s La Liga action, as the trio of Messi-Suarez-Neymar continues to terrorize defenses.

Barcelona 4-0 Real Sociedad

In case you haven’t heard, Barcelona is scary good. Coming off of brilliant 4-0 and 6-1 wins over Real Madrid and Roma respectively, the Catalans trounced Real Sociedad at Camp Nou. It was the usual suspects once again, as Lionel Messi, Luis Suarez, and Neymar (x2) scored the goals in another masterful performance. The M-S-N trio has accounted for 30 of Barcelona’s 33 goals in La Liga this season.

Atletico Madrid 1-0 Espanyol

While the boys from Barcelona may be getting all the headlines, Antoine Griezmann has been having a great season for Atletico Madrid. The French international scored the game-winner in Atletico’s 1-0 win over Espanyol, his tenth in all competitions this season. The good news is that Atleti sit second on the table with a five-point lead over Real Madrid in third, while the bad news is that midfielder Tiago broke his leg in the match.

[ WATCH: Everton, Bournemouth trade late goals in stoppage-time thriller ]

Malaga 2-2 Granada

In a battle of teams fighting for La Liga survival, Granada came from behind to steal a draw at Malaga. The home-side was leading 2-0 until Granada tallied twice in the final ten minutes to take a huge point for the club. Malaga remains glued to the bottom of the table, while Granada is currently out of the drop zone on goal differential.

Elsewhere in La Liga

Levante 0-1 Real Betis
Las Palmas 0-2 Deportivo
Celta Vigo 2-1 Sporting Gijon
Getafe vs. Villarreal (Sunday, 6 a.m. ET)
Eibar vs. Real Madrid (Sunday, 10 a.m. ET)
Rayo vs. Athletic Bilbao (Sunday, 12:15 p.m. ET)
Sevilla vs. Valencia (Sunday, 2:30 p.m. ET)