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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.

MLS Snapshot: Colorado Rapids 1-1 FC Dallas (video)

COMMERCE CITY, CO - JULY 23: Marlon Hairston #94 of Colorado Rapids celebrates after scoring a first half goal past Chris Seitz #18 of FC Dallas during a game at Dick's Sporting Goods Park on July 23, 2016 in Commerce City, Colorado. (Photo by Dustin Bradford/Getty Images)
Photo by Dustin Bradford/Getty Images
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The game in 100 words (or less): In keeping with the the theme of “we never really learn anything in MLS, it just kind of happens,” both the Colorado Rapids or FC Dallas had the chance to make a massive statement in the two sides’ ongoing race for the Western Conference and Supporters’ Shield (FCD entered Saturday’s clash at Dick’s Sporting Goods Park with a three-point lead), but they ultimately settled for a 1-1 draw, and we settle for “wait until next week, maybe we’ll actually learn something then.” At least the goals were great, though — Marlon Hairston opened the scoring by rounding the goalkeeper with traffic in all directions, and Victor Ulloa unleashed a rocket from well outside the penalty area to equalize late on. In that sense, the 90 minutes were befitting a first-versus-second matchup. The draw means the Rapids are unbeaten in their last 15 league games, but the LA Galaxy, who won away to the Portland Timbers and inched two points closer to the league’s elites, are ultimately the day’s biggest winners.

[ MORE: Previewing the rest of the MLS weekend ]

Three Four moments that mattered

26′ — Akindele goes inches wide of the far post — Quick, decisive movement around the penalty area is the only way to create that half-yard of space needed to fire a shot off.

33′ — Hairston breaks out, Zimmerman makes the dramatic block — Hairston was thisclose to having a one-on-one chance on goal, but Walker Zimmerman made a spectacular recovery run and an even better last-second sliding tackle to deflect Hairston’s shot narrowly wide of the post.

44′ — Hairston rounds Seitz to make it 1-0 — Composure, quickness, finesse. Hairston displayed it all on this goal, his second in as many games.

82′ — Ulloa unleashes a blast from 25 yards out f0r 1-1 — If not for the net on the goal, Ulloa’s strike might still be traveling at an ever-so-slightly upward trajectory for the rest of time.

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Man of the match: Sam Cronin

Goalscorers: Hairston (44′), Ulloa (82′)

MLS Snapshots: Impact 5-1 Union | Toronto FC 4-1 DC United (video)

Didier Drogba
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The game in 100 words (or less): Look out, America, for the Canadians of Major League Soccer are here, and they mean business. Saturday night saw the Montreal Impact and Toronto FC thrash the Philadelphia Union (5-1) and D.C. United (4-1), two playoff-caliber teams in their own right, each at home, to move to within four and six points, respectively, of New York City FC, the current leaders of the Eastern Conference. The stars for the two sides? Would you believe me if I told you Sebastian Giovinco and Didier Drogba each scored a hat trick on the night? Of course you would, because they’re Giovinco and Drogba. At their best, it’s hard to argue any team in the East is better than either Montreal or Toronto. Here’s to 180 minutes of Drogba vs. Giovinco in the Eastern Conference finals.

[ MORE: Previewing the rest of the MLS weekend ]

Three moments that mattered

19′ — Silky smooth build-up ends with a Drogba tap-in — If you’re allowing Drogba chances that are this easy, good luck to you. The real story here, though, is the backheel by Piatti. A moment like this is enough to flip me into a second-assist advocate.

42′ — Drogba slots home a rebound for 2-0 — Unlucky carom on the rebound, but you’re really not doing a great job of “don’t give Drogba chances that are that easy,” Union defense.

52′ — Drogba gets his hat trick — The Union are really, really not doing a good job of making life even the least bit difficult for Drogba.

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Man of the match: Didier Drogba

Goalscorers: Drogba (19′, 42′, 52′), Pontius (72′), Piatti (87′), Mancosu (90+1′)


Three moments that mattered

21′ — Giovinco ends his skid with a stunning free kick — It had been eight full games since Giovinco last scored a league goal for TFC, by far the longest such streak of his time in MLS. The wait was (almost) worth it. (WATCH HERE)

39′ — Giovinco does it again — What is there to say at this point? The angle is ridiculous. The power is ridiculous. The swerve is ridiculous. Giovinco is a ridiculous player. (WATCH HERE)

90+1′ — A hat trick for Seba — Not to be outdone, Giovinco bags his third of the night.

[ FOLLOW: All of PST’s MLS coverageStandings | Stats | Schedule ]

Man of the match: Sebastian Giovinco

Goalscorers: Giovinco (21′, 39′, 90+1′), Jeffrey (24′), Delgado (29′)

WATCH: Giovinco’s goal drought is over after a pair of stunning free kicks

Toronto FC's Sebastian Giovinco celebrates after scoring his team's second goal against Colorado Rapids during the first half of the MLS soccer game in Toronto on Saturday, Sept. 19, 2015. (Chris Young/The Associated Press via AP)
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Oh, how we have missed you, Sebastian Giovinco, scorer of amazingly beautiful, video game-like goals.

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If you can believe it, Toronto FC’s tiny superstar entered Saturday’s clash with D.C. United without a goal in any of his last eight league games. Six minutes before halftime, the drought was over after not one, but two “only Giovinco could do that” free kicks (videos below).

[ MORE: Previewing the rest of the MLS weekend ]

It was by far the longest such streak of Giovinco’s (brief) time in MLS, and at least he had the decency to make it worth our wait.

Scholes: Pogba “nowhere near worth” rumored Man United transfer fee

MANCHESTER, ENGLAND - AUGUST 05:  Paul Pogba of Manchester United looks on during Paul Scholes' Testimonial Match between Manchester United and New York Cosmos at Old Trafford on August 5, 2011 in Manchester, England.  (Photo by Chris Brunskill/Getty Images)
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If a player is only worth what a club is willing to pay them, then aren’t they also worth a price at the top of the pay scale, as long as a club is willing to pay it?

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Manchester United legend Paul Scholes doesn’t think so, at least not in the case of Paul Pogba, the highly-sought Juventus (and former Man United, which he left for free) midfielder. Rumored to be the subject of $113-million bid by the Red Devils, Pogba’s footballing future remains a question, though an answer will have to be realized in the coming days and/or weeks, as the 2016-17 Premier League season kicks off 21 days from today.

That’s a price that, according to Scholes, should be reserved for “someone who is going to score 50 goals a season like Ronaldo or Messi” — quotes from the Guardian:

“He was a very talented young player, I played with him and I knew how good he was. He played for the first team maybe once or twice, but from my understanding he was asking for too much money [when he left in 2012].

“For his age, he was asking for far too much money, for a player who hasn’t played first-team football. OK, he has gone on to great things. I think certainly there has been a lot of improvement. He needed to improve if he is going to be a player worth £86m.”

While United may have to pay closer to [$131 million], Scholes added: “I just don’t think he is worth [$86 million]. For that sort of money, you want someone who is going to score 50 goals a season like Ronaldo or Messi. Pogba is nowhere worth that kind of money yet.

[ PRESEASON: PL clubs in action with opening day three weeks ago ]

On Scholes’ assertion that Pogba was asking “for far too much money”: United have finished 7th, 4th and 5th in the last three PL seasons, while in that same time Pogba has gone on to become on of the top five players in the world; meanwhile, none of the world’s 20 best (or is it 50?) players currently play for United. It would have been a risk to pay a 19-year-old with three first-team appearances like a seasoned veteran, to be sure, but so much of succeeding at the top level of the sport is down to hitting pay dirt on exactly that kind of calculated risk. If everyone plays it by the book, no one’s ever going to get ahead.

On Scholes’ obviously fear he may no longer be United’s greatest “Paul”: It’s OK, Scholesy, it’ll be terribly difficult to top in 10 years what you achieved in 18.