In my passion to better understand how soccer is statistically tracked I’ve come across what I would call is an oddity about the general characterization of “passing” in the world’s greatest sport.
Here’s the deal – go to Squawka.com, whoscored.com, reference the “Stats” tab on mlssoccer.com, or review Golazo information, and you’ll notice they all provide passing information.
My intent is not to dig deep into passing details – not yet, anyway. We’ll get there in another article to follow after I get permission from OPTA to reference their F-24 definitions within their Appendices. For now here’s a simple question I have as a statistical person working on soccer analysis.
What is the number of passes I should use for teams and which denominator is the right number for total passes by both teams to help determine possession percentages?
In the MLS Chalkboard you can clearly see and count passes – here’s an example from a game this past week.
An important filter to note – the major term ‘Distribution’ is not to be clicked in creating this filter – all that is clicked is ‘successful pass and unsuccessful pass’; note also that some details are provided on the types of passes – we’ll get there in another article.
Bottom line is that the MLS Chalkboard identifies 309 successful passes and 125 unsuccessful passes for a total of 434 passes attempted.
On the MLS Stat sheet – one tab over but linked here the number of passes for Chivas = 369; that number doesn’t match the Chalkboard in either total, unsuccessful or successful.
For Golazo, for that same game here’s their total: 369 Passes total with 75% accuracy meaning the total successful passes was 277 and unsuccessful passes totaled 92. Not the same either.
For Squawka.com here’s their total:
Successful = 270 /// headers (8), throughballs (2), passes (239), long balls (21) and supposedly crosses (0)
Unsuccessful = 86 /// passes (52), headers (14), long balls (20), no unsuccessful crosses or throughballs logged here?! Yet the MLS chalkboard indicates 26 unsuccessful crosses!
All told that is 356 passes; those figures don’t match the other data sources.
For whoscored.com here’s their total: Short ball = 323, Long ball = 52, Through ball = 2, Cross = 35, for a total of 412 passes – again that figure doesn’t match the other data sources.
So what’s the right total? Here’s a table to compare showing the source of data and the total passes submitted for statistical folks like us to leverage in our analysis.
|Golazo (same as MLS Stats)||369|
I have no idea what ‘right’ looks like here but here’s what I’ve done to work through this issue.
I chose one source, the MLS Chalkboard, to gather and analyze statistics on passing and possession and all other things available from that data source – where other information is not offered there I reference the MLS Stats tab and Formation tab.
Why did I choose the Chalkboard? Because it provides additional detail that shows more clarity on all the other types of passes that occur in a game.
For example; if you scroll down on the Chalkboard link and select Set-Pieces you’ll see that Throw-ins are included in the successful passing totals – by definition a Throw-in is a pass as it travels from one player to another.
So my recommendation, if interested, is to track Major League Soccer statistics using the MLS Chalkboard first – it’s harder but seems to be the best one at this time.
I’m not sure why the MLS Chalkboard, Golazo, Whoscored and Squawka all had different team passing statistics; given that it is likely they all have different individual player statistics as well… but in asking a representative from OPTA about that – their response was provided below:
“The difference between the different websites could be down to a few things. Either they take different levels of data from us, or they take the same feed but only use a chosen set of information from each feed to display their own take on each game.”
By the way – I did try to find a reasonable definition of what a pass is defined as for soccer; here’s some of that information before final thoughts… note: they are all different and Wikipedia proves, by its definition, why it’s a pretty useless source for information… for them a pass in soccer must travel on the ground – no kidding – here’s their definition up front:
“Passing the ball is a key part of association football. The purpose of passing is to keep possession of the ball by maneuvering it on the ground between different players and to advance it up the playing field.”
Other definitions get pretty detailed – it is what it is apparently – complicated…
Passing Definition: About.com World Soccer.
When the player in possession kicks the ball to a teammate. Passes can be long or short but must remain within the field of play.
Soccer Dictionary: Note there are numerous definitions provided in this link so offering up a specific link is troublesome so I will cut and paste those definitions below:
Cross, diagonal: Usually applied in the attacking third of the field to a pass played well infield from the touch-line and diagonally forward from right to left or left to right.
Cross, far-post: A pass made to the area, usually beyond the post, farthest from the point from which the ball was kicked.
Cross, flank (wing): A pass made from near to a touch-line, in the attacking third of the field, to an area near to the goal.
Cross, headers: 64% of all goals from crosses are scored by headers.
Cross, mid-goal: A pass made to the area directly in front of the goal and some six to twelve yards from the goal-line.
Pass, chip: A pass made by a stabbing action of the kicking foot to the bottom part of the ball to achieve a steep trajectory and vicious back spin on the ball.
Pass, flick: A pass made by an outward rotation of the kicking foot, contact on the ball being made with the outside of the foot.
Pass, half-volley: A pass made by the kicking foot making contact with the ball at the moment the ball touches the ground.
Pass, push: A pass made with the inside of the kicking foot.
Pass, sweve: A pass made by imparting spin to the ball, thereby causing it to swerve from either right to left or left to right. Which way the ball swerves depends on whether contact with the ball is made with the outside or the inside of the kicking foot.
Pass, volley: A pass made before the ball touches the ground.
Passing: When a player kicks the ball to his teammate.
Through pass: A pass sent to a teammate to get him/her the ball behind his defender; used to penetrate a line of defenders. This pass has to be made with perfect pace and accuracy so it beats the defense and allows attackers to collect it before the goalkeeper.
Ducksters.com offers up a Glossary and Terms for Soccer; here’s what they define a pass as being… this one is geared more towards teaching players about various types of passes they will need good skill in order to execute them.
Direct Passes – The first type of soccer pass you learn is the direct pass. This is when you pass the ball directly to a teammate. A strong firm pass directly at the player’s feet is best. You want to make it easy for your teammate to handle, but not take too long to get there.
Passes to Open Spaces – Passing into space is an important concept in making passes in soccer. This is when you pass the ball to an area where a teammate is running. You must anticipate both the direction and speed of your teammate as well as the opponents. Good communication and practice is key to good passes into space.
Wall Passes (One-Twos) – Now we are getting into more complex passing. You can think of a wall pass as bouncing a ball off of a wall to yourself. Except in this case the wall is a teammate. In wall pass you pass the ball to a teammate who immediately passes the ball back to you into open space. This helps to keep the defense off balance. This is a difficult maneuver and takes a lot of practice, but the results will make it worth the effort.
Long Passes – Sometimes you will have the opportunity to get the ball up the field quickly to an open teammate. A long pass can be used. On a long pass you kick the ball differently than with other shorter passes. You use an instep kick where you kick the soccer ball with your instep or on the shoelaces. To do this you plant your non-kicking foot a few inches from the ball. Then, with your kicking leg swinging back and bending at the knee, snap your foot forward with your toe pointed down and kick the ball with the instep of your foot.
Backward Pass – Sometimes you will need to pass the ball backward. This is done all the time in professional soccer. There is nothing wrong with passing the ball back in order to get your offense set up and maintain control of the ball.
Now that’s probably not ‘every’ definition available but they pretty much say the same thing apart from ‘on-the-ground’ by Wikipedia – a pass is a transfer of the ball from one player to another…
As noted earlier – I’m not really sure what right looks like but I remain convinced that all these organizations are well-intentioned in offering up free statistics for others to use, be it for analysis, fantasy league or simply to check it out.
In my own effort to develop more comprehensive measurements and indicators a standardized source of data for the MLS would be beneficial – if the intent for MLS is to endorse OPTA then there remains a conflict as Golazo clearly does not use the same data filters as the Chalkboard.
My vote, is and will remain, keep the Chalkboard and then, MLS, consider ways, as OPTA (Perform Group) is now, to improve it for more beneficial analysis.
Here is Part II – where I peel back a wee bit more – consider these phrases, successful crosses, launches, key passes, through-balls, throw-ins and more, as ASA continues its venture into Soccer Analysis in America.
Here’s a few paraphrased thoughts from other folks who offer up articles on ASA about this issue on passing statistics:
Jared Young – The massive difference in pass data between sites is troubling and disturbing; I’ve been primarily using whoscored.com and golazo for my numbers so I may have to explore other options.
Cris Pannullo – Major League Soccer should take an initiative and define what pass means in their league; it is surprising that they haven’t given how popular things like fantasy sports are; people eat statistics up in this country.
All the best, Chris
You can follow me on twitter @chrisgluckpwp
If you read my initial article on “Passing – An oddity in how it’s measured in Soccer Part I“; I hope you find this article of value as well as the onion gets peeled back a bit further to focus on Crosses.
To begin please consider the different definitions of passing identified in Part I and then take some time to review these two additional articles (Football Basics – Crossing) & (Football Basics – The Passing Checklist) published by Leo Chan – Football Performance Analysis, adding context to two books written by Charles Hughes in 1987 (Soccer Tactics and Skills) and 1990 (The Winning Formula). My thanks to Sean McAuley, Assistant Head Coach for the Portland Timbers, for providing these insightful references.
In asking John Galas, Head Coach of newly formed Lane United FC in Eugene, Oregon here’s what he had to offer:
“If a cross isn’t a pass, should we omit any long ball passing stats? To suggest a cross is not a pass [is] ridiculous, it is without a doubt a pass, successful or not – just ask Manchester United, they ‘passed’ the ball a record 81 times from the flank against Fulham a few weeks back.”
In asking Jamie Clark, Head Coach for Soccer at the University of Washington these were his thoughts…
“It’s criminal that crosses aren’t considered passing statistically speaking. Any coach or player knows the art and skill of passing and realizes the importance of crossing as it’s often the final pass leading to a goal. If anything, successful passes should count and unsuccessful shouldn’t as it’s more like a shot in many ways that has, I’m guessing, little chance of being successful statistically speaking yet necessary and incredibly important.”
Once you’ve taken the time to read through those articles, and mulled over the additional thoughts from John Galas and Jamie Clark, consider this table.
|Stat||Golazo/MLS STATS||Squawka||Whoscored||MLS Chalkboard||My approach||Different (Yes/No)?|
|Total Passes||369||356||412||309+125 = 434||309+125+9=443||Yes|
|Total Successful Passes||277||270||305||309||309 + 9 = 318||Yes|
|Passing Accuracy||75%||76%||74%||NOT OFFERED||71.78%||Yes|
|Possession Percentage||55.30%||53%||55%||NOT OFFERED||55.93%||Yes|
|Final Third Passes||141||NOT OFFERED||NOT OFFERED||FILTER TO CREATE||140||Yes|
|Final Third Passing Accuracy||89/141= 63.12%||NOT OFFERED||NOT OFFERED||FILTER TO CREATE||92/140 = 65.71%||Yes|
|Total Crosses||35 vs 26 (MLS Stats)||NOT OFFERED||35||35||35||No|
|Successful Crosses||35*.257=9||NOT OFFERED||9||9||9||No|
|KEY PASSES||NOT OFFERED||7||9||6||6||Yes|
|* NOTE: MLS Chalkboard includes unsuccessful crosses as part of their unsuccessful passes total but does not include successful crosses as part of their total successful passes; it must be done manually.|
For many, these differences might not mean very much but if looking for correlations and considering R-squared values that go to four significant digits these variations in datum might present an issue.
I don’t track individual players but Harrison and Matthias do, as does Colin Trainor, who offered up a great comment in the Part I series that may help others figure out where good individual data sources might come from.
My intent here is not to simply offer up a problem without a solution; I have a few thoughts on a way forward but before getting there I wanted to offer up what OPTA responded with first:
I (OPTA representative) have has (had) a word with our editorial team who handle the different variables that we collect. There is no overlay from crosses to passes as you mentions, they are completely different data variables. This is a decision made as it fits in with the football industry more. Crosses are discussed and analysed as separate to passes in this sense. We have 16 different types of passes on our F24 feed in addition to the cross variable.
So OPTA doesn’t consider a cross a pass – they consider it a ‘variable’?!?
Well I agree that it is a variable as well and can (and should) be tracked separately for other reasons; but for me it’s subservient to a pass first and therefore should be counted in the overall passing category that directly influences a teams’ percentage of possession. Put another way; it’s a cross – but first and foremost it’s a pass.
(Perhaps?) OPTA (PERFORM GROUP now) and others in the soccer statistics industry may reconsider how they track passes?
I am also hopeful that OPTA might create a ‘hot button’ on the MLS Chalkboard that allows analysts the ability to filter the final third consistently, from game to game to game, as an improvement over the already useful ‘filter cross-hairs’…
My intent is not to call out any statistical organizations but to offer up for others, who have a passion for soccer analyses, that there are differences in how some statistics can be presented, interpreted and offered up for consideration. In my own Possession with Purpose analysis every ball movement from one player to another is considered in calculating team passing data.
Perhaps this comparison is misplaced, but would we expect the NFL to call a ‘screen pass’ a non-pass and a variation of a pass that isn’t counted in the overall totals for a Team and Quarterback’s completion rating?
Here’s a great exampleon how Possession Percentage is being interpreted that might indicate a trend.
Ben has done some great research and sourced MLS Stats (as appropriate) in providing his data – he’s also offered up that calculating possession is an issue in the analytical field of soccer as well.
In peeling back the data provided by MLS Stats he is absolutely correct that the trend is what it is… When adding crosses and other passing activities excluded by MLS Stats the picture is quite different and lends credence to what Bradley offers.
For example–when adding crosses and other passing activities not included by MLS Stats–the possession percentages for teams change, and the R-squared between points in the league table comes out as 0.353, with only 7 of 8 possession-based teams making the playoffs. New York, with most points, New England and Colorado all had possession percentages last year that fell below 50%, and only one team in MLS last year that didn’t make the playoffs finished with the worst record (16 points) DC United.
For me, that was superb research – a great conclusion that was statistically supported. Yet, when viewed with a different lens on what events are counted as passes, the results are completely different.
All the best,
You can follow me on twitter @chrisgluckpwp
While most were probably focused on some other battles this past weekend – and rightly so in some cases – the Timbers might just have shaken the Western Conference a wee bit to reinforce, that when they get their defense right, they will be a team to reckon with.
Before diving in though; here’s a link to my pre-match thoughts on all the games this weekend; some thoughts are smack on – while some are way off target; so it goes.
Back to the Timbers.
I don’t offer this lightly, for almost 80% of this season the Timbers defense has been downright deplorable (just three clean sheets) last year they had 10 clean sheets after 25 games.
Only now – with a major shakeup in the back-four, after that resounding Sounders smack-down, have the Timbers acknowledged that defense is first and played like it!
The star of the match, and I don’t do this often since team is always first, was a young lad by the name of Alvas Powell – here’s a great picture of him post game with the ever present, and highly entertaining Pa Madou Kah, in the background – picture courtesy of Little Imp (@stretchiegirl)
So before digging into some specific statistics about the Timbers here’s a link to my post-match article, about that game, and then the Composite PWP Strategic Index for Major League Soccer after 25 weeks:
One other technical detail that’s probably new for many – the yellow stars indicate which teams have already sacked their manager this year.
I’ll offer up a reminder a bit later on all the stars present at the end of last year.
And if you are interested in some details about why Toronto FC sacked Ryan Nelson – I’ve included this article published by MLSSoccer.com for your reading pleasure.
To summarize, based upon what I took away from the article, Ryan Nelson was sacked due to poor team performance. I’m not sure what that means to the Toronto front office but it’s meaning (could?) be intuited based upon this Index. I’ll leave that for others to decide.
So now on to overall team performance:
LA Galaxy, Seattle Sounders, and Sporting KC continue to lead the overall CPWP Index – others moving up or staying put in the top half include Columbus, DC United, Portland Timbers, FC Dallas, New England, Real Salt Lake; while New York, Colorado, and Vancouver took slight dips this week.
On the outside, looking in, the list is much shorter. Of note to me, is that only two of those teams performing on the trailing end are Western Conference teams.
Can some conclusions be drawn from that? Perhaps – but I’ll save those thoughts for when the season is completed.
Attacking PWP Strategic Index:
For the statistical types; the R2 between the APWP Strategic Index and Points in the League Table is .74 – that’s also pretty good.
Leading the league are the LA Galaxy (no surprise I’d expect). On the tail end there’s Chivas and the ever shocking Dynamo, especially for some, after beating Sporting KC this weekend. Somehow I don’t think Houston is entirely out of the Playoff picture.
With respect to Portland they are sixth best in possession percentage, passing accuracy within the final third, and goals scored per shots on goal – pretty consistent in three critical attacking indicators.
With regards to overall passing accuracy they are in the top ten at 8th best. When converting possession to penetration they are also 8th best – and in shots on goal per shots taken they are 7th best.
In looking at shots taken, per penetrating possession, (a percentage number usually better when lower than higher to infer patience) they are 11th best.
So all told, in attack, they are very consistent, and good, compared to others.
Their downfall has come in Defending PWP – here’s how the teams stack in that Strategic Index after Week 25:
For the statistical folks the DPWP Strategic Index R2 is -.66 – again pretty good but there is a tricky quirk about defending.
There remains a challenge in measuring what doesn’t happen (for the attacking team) based upon how the defense plays.
In other words some positional activities that the defense executes are never measured – what gets measured are actual events as opposed to non-events; i.e tackles, interceptions, clearances, etc…
One of my recent articles was published with the intent to push professional soccer statistical companies to begin tracking and differentiating between Open Passes and Hindered Passes, as well as Open Shots and Hindered Shots, to help measure what doesn’t happen.
“Well an attacking player decides he can’t make a pass to a player in a forward position because the defender has the passing lane closed (hindered) – so the attacker passes elsewhere (an open pass that is unopposed).
In counting the number of Open Passes versus Hindered Passes statistical types can begin to plot maps on what areas the defense is inclined to leave open (cede) versus what areas they are inclined to hinder (defend against).
When graphing those Open Passes versus Hindered Passes you can now infer (statistically measure) what doesn’t happen; i.e the ball is “not being passed successfully here”…
Put another way – if a player has the ability to make an Open Cross – that is completed. What didn’t happen is the fullback didn’t close on the winger and the center-back didn’t clear the ball.
If the Cross was a hindered cross then the value of defending can be determined even more. If it was a Hindered Pass that results in a shot taken then the fullback was not positioned properly to block the cross – nor was the center-back positioned correctly to clear the cross… Again – a statistical measurement of what doesn’t happen…
As a Youth Head Coach that type of information would be extremely critical to know when developing training plans between games… in considering how much money is involved at the professional level I would have thought the value would be even greater. Perhaps others may have a different view on that?
I’m not sure how clear that is but I’ll try to provide a few more examples as time passes… for now my early thoughts also include differentiating between an Open Throw-In and Open Cross versus Hindered Throw-In and Hindered Cross.”
In looking specifically at the Portland Timbers this year – they 10th (mid-table) in the DPWP Strategic Index – not bad by all accounts.
In peeling back the Defending Indicators they are 4th best in limiting their opponents passing accuracy (75.73%); they are 6th worst in preventing their opponents from completing passes in their defending final third (66.75%).
In terms of Possession percentage; teams average 47.38% – 6th lowest in MLS.
When looking at opponent shots taken per penetrating possession it’s 8th worst (18.85%)- and the percentage of opponents shots taken being on goal is 9th worst (36.72%).
Most critical (the weakest link it appears) is that the percentage of opponent possession leading to penetration is 26.48% (the worst in MLS). What this means is that over 25% of the time that the opponent has the ball they penetrate the Timbers final third… All told the final indicator (goals scored per game) is 3rd worst (1.65).
So how about the game against Vancouver?
- Vancouver had 45.57% possession – lower than the Timbers average.
- Vancouver passing accuracy across the entire pitch was 82% – higher than the Timbers average.
- Vancouver had 73% passing accuracy within the Timbers final third – higher than the Timbers average.
- Vancouver had 28.49% of their overall possession result in penetrating the Timbers final third – higher than the Timbers average.
- Vancouver had 10.27% of their shots taken per penetrating possession – lower than the Timbers average.
- Vancouver had 33.33% of their shots taken being shot on goal – lower than the Timbers average.
- Vancouver had 0% of their shots on goal result in a goal scored – lower than the Timbers average.
In conclusion: Here’s what happened in simple terms.
Portland ceded some space outside and slightly higher, within their defending third, in order to minimize the time and space Vancouver had in having their shots taken end up in the back of the net.
So while Portland didn’t park the bus they did get behind the ball, as much as possible, in an attempt to minimize risk… not rocket science – just good defensive team management.
Every game, for almost every team, is a ‘must win’ at this stage of the season – the ironic thing is that phrase has really been an accurate phrase for every game this season.
The earlier you consistently win games the less ‘must-ful’ they become as the season ends.
The exceptions to this, at this time, are probably Chivas USA and Montreal Impact.
Neither have a credible chance of making the playoffs – so those early season and mid-season games they lost were really their MUST win games – and of course, they didn’t win them.
As promised a reminder on coaching changes from last year; here’s the End of Season CPWP Strategic Index showing all the teams (stars) that had changes in Head Coaches during or after the season:
Note that five out of the six worst teams in PWP team performance saw coaching changes – and seven out of the bottom ten. Will we see that sort of house-cleaning again this year?
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Roughly 10 days before the Kickoff to the first ever World Conference on Science and Soccer held in the United States I got a phone call from the Conference President and Coordinator Terry Favero asking me if I was interested in making a presentation on Possession with Purpose.
To say the least I was pleasantly surprised, elated and nervous all at the same time; me – just a wee blogger locked up here in the great northwest; a hot bed for soccer being asked to offer my work on Possession with Purpose.
In short; after a some discussion and clarification I said yes; and four days later had submitted this presentation for discussion.
Before showing the diagrams, my first order of business is to thank Terry Favero, and then also add my thanks to some great folks at Prozone Sports, New England Revolution, Portland Timbers and Arsenal FC for making the presentation and discusssion truly superb! Wow – what a great experience.
Without further ado; let the diagrams begin…
Wrapping up the hour long presentation/discussion with a few takeaways that come to mind…
Most agreed that the critical penetration numbers to focus on were passes “within” the Final Third and not just passes that “penetrate” the Final Third.
Most agreed that crosses ‘were’ passes – though there also remains value in considering crosses separately – but they should be included in the overall analysis of passing accuracy within the Final Third.
New Soccer Statistics?
- Additional discussion centered on the potential need for a couple of new statistics – “failed assists” was one – …there is value in knowing what players offer up what volume of potential goal scoring opportuinities even if they fail – especially those that fail as a result of a defensive clearance.
- In that example the defender gets credit for stopping a cross but the player who offers the cross that is good enough to require a clearance gets no statistical credit for it… that may change in the near future.
- Another additional new statistic considered was the ‘penetrating pass’ statistic – where individual players who generate penetrating passes into the Final Third are recognized… it’s hard to measure vision but many agreed this may be a statistic that could help measure ‘vision’…
The slide highlighting the changes in MLS Coaches from 2013 to 2014 also peaked some interest – indeed – like last year – the cycle has begun again this year with the sacking of John Hackworth.
I’ve done two separate articles on that and won’t go into any more detail other than to say – my team performance indicators lean towards that move being one of senior leadership panic (with the lack of wins) more than anything else.
Granted wins matter – but the last slide really drives home how an organization, loyal to their Head Coach, can turn things around with minimal changes in personnel and faith in the system being used.