Stoke’s One Direction

This is a very short article which doesn’t contain anything groundbreaking, however I wanted to post a viz which says something amazing about Stoke.

By this stage everyone knows that Stoke’s gameplan revolves around set pieces, long balls and flick ons. However, I was surprised at just how one dimensional they actually are.

This image shows the ground shots (headers and penalties are excluded) that Stoke scored with during the 2012/13 Premier League season:

Stoke3

There is no need to correct your screen, all the white space on that image is correct!!

Stoke scored 21 goals from ground shots, but 20 of them came from what I have termed the Prime Positions, ie the central portion of the penalty area.
They only scored 1 kicked goal all season which was not from this centrally close position!!  This was the thunderbolt scored by Cameron Jerome in the 90th minute versus Southampton which earned his team a point.

Their inability to score from the ground unless the shot was from very close central positions is bound to have left Stoke a fairly easy team to defend against.
Well maybe, “easy to defend against” is not the correct phrase but their lack of variation will certainly have counted against them.
Although he was coming from a different viewpoint,  Mike Goodman pointed out why variety in a team’s attacking attacking play is so important.

Context

In order to give Stoke’s total lack of variety some meaning, here is a table which ranks each team by the proportion of their ground hit goals that  came from the Prime Position.  Before that however, I’m also including an image that defines the boundaries of the Prime Position.

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% of Ground Goals from Prime Location

prime

The above table clearly shows just how much more reliant Stoke were on scoring ground shots from close in locations than any other team in the league.
After their 95% figure there is a lot of clear air until we reach the 71%s that were posted by Man United and Southampton.

Tony Pulis

I know I’m not the first person to say that Stoke were correct in dispensing with the services of Tony Pulis at the end of last season, but the figures contained in the above table seem to give great weight to the fact that Stoke City football club just had to do something to try to spark a change in the way that they play.

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Liverpool’s Defensive Weakness

When compiling the recent article that I posted where I looked at where teams conceded shots from I came across some interesting findings in relation to Liverpool.

We’ll go for a slight recap and start with the good news for Liverpool; as a defensive unit they were extremely successful at forcing teams to take shots from poor shooting locations:

ShotsConceded

So good were Liverpool in forcing teams to shoot from non optimum positions that they only permitted 18% of shots to come from what I have defined as the Prime location.  As you can see, this value ensured that they led the league quite comfortably in terms of this particular metric.  Of course this fact raises potential questions around how Reina performed in keeping out shots given the great job that his defence did in front of him.  That question can remain unanswered until another day.

I want to look at another feature of Liverpool’s defending that caught my eye; which side of the pitch did the conceded shots originate from.

Background

It surprised me a little to see that 47% of all the shots (excluding headers and penalties) in the Big 5 European leagues last season came from left of centre, 19% were straight on and just 34% came from an area to the right of centre.  I can only presume that the large number of shots from the left side of the pitch is due to the predominate use of the right foot when shooting.  It is obviously much more natural for right footed players to shoot from the left hand side.

From a defence viewpoint the image below shows the areas of the shooting zone that I am defining as right, left and centre of defence:

SidesTemplate

Which side of the pitch did the Premier League teams concede shots from last season?

EPLSidesConcede

Remember, this table is from a defensive viewpoint, and has been sorted in descending order on the Right hand side.

Although there is a heavy bias to all teams conceding shots from their right hand side (this is obviously the other side of the coin to more shots being struck from the attacker’s left side), Liverpool allow a greater proportion of shots to come from their right hand side than any other team in the league.  The league average for conceding shots from the right hand side was 47% but Liverpool allowed in excess of 54% of their shots to be struck from their right hand side.

Their figure conceded down the right of 54.4% is more than 2.5 standard deviations from the league mean which is significant at a level of 1%, or in layman’s terms “there is definitely something happening that causes so many shots to come from Liverpool’s right hand side”.

Is Glen Johnson at fault?

The first possible explanation for this fact that jumped into my head was “Glen Johnson”.  Although Glen Johnson offers Liverpool great attacking potential, in fact he averaged 1.5 shots per game last season which put him just behind David Luiz in terms of attempts by defenders; perhaps these attacking forays come at a price to Liverpool.
I am aware that Johnson didn’t play every game last season and I haven’t yet went to the trouble to separate the shooting statistics for the games that he did play versus the games that he missed.

Whatever the explanation it certainly seems that Liverpool is much more open on their right hand side than any other team in the Premier League.  It’s safe to assume that this fact won’t have gone unnoticed by Premier League managers.

I’m interested to hear any other possible explanations for the heavy bias of shots conceded down Liverpool’s defensive right side.

Where did teams concede shots from?

All the shooting location analysis work I have done so far has concentrated on the attacking sides, so I thought it about time that I looked at the other side of the coin; how teams defended.  In my previous article I concluded that headers are a lot less dangerous to concede than shots.
With that in mind, and for the purposes of this article, I thought I would strip out headers (as well as penalties), and thus we are left with just non-headed attempts on goal.

As before, in order to aid analysis, I have divided the shots conceded by each team into four different areas which are colour coded as per the legend below.

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Here is the summary of shots conceded by each team in the 2012/13 Premier League season:

ShotsConceded

I have listed the number of shots that each team conceded, and then showed the percentage of shots that each team allowed in each of the four areas.  The last two columns show the combined proportion and number of shots that each team allowed in the two best areas for shooting, the Prime and Secondary areas.
The table has been sorted by Prime and Secondary Percentage in ascending order.

Liverpool

The team that sits atop of this table is Liverpool.  They permitted less than 55% of the shots they conceded to be struck from the Prime and Secondary areas, and they were the only team in the league to allow less than 20% of their shots conceded to come from the Prime area (18%).
There is no getting away from the fact that Liverpool put in a tremendous defensive performance during the season just ended. For this they should receive a lot of credit.

Stoke

The appearance of Stoke or “PulisBall” as described by MarkTaylor in second position will come as no surprise to analytics aficionados.  Pulis puts (or should that be “put”) great store on his team taking shots from good locations and preventing the opposition from doing likewise.

QPR

QPR are interesting.  For a team that struggled so badly I was surprised to see them sitting as high as 5th in this table with just over 62% of shots conceded from the Prime and Secondary areas.  Of course, the quantity of shots they allowed at 489 would somewhat counteract that last statement.

Tottenham

Although Tottenham appear towards the bottom of this table with a relatively poor 66% of shots permitted to be taken from the Prime & Secondary positions the fact that they conceded a league low 297 shots resulted in them conceding the fewest number of shots from the two most attractive shooting areas.

Reading

From a defensive viewpoint Reading stank the place out.  At 591 they conceded the highest number of shots and the positions they allowed those shots to be taken from were just as horrendous.

Hopefully the above table will serve as a useful point of reference for anyone that wants to see how a particular team did in terms of the number, or more importantly, location of shots they permitted last season.
I’m also that sure this won’t be the last time that I look at the type of shots that teams permitted.

A Few Italian Heatmaps

Ben Boucher asked me if I could post heatmaps of a few Italian teams for 2012/12 season.

The usual format applies:

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I’ll look at the Top 3 teams in league order:

Juventus

Juventus

Napoli

Napoli

Milan

Milan

…..and then Inter who finished the season down in 9th

Inter

Inter

On the face of it those heatmaps are not very different for any of the 4 teams, and so the shooting locations wouldn’t seem to explain many differences in league placings.

Team Heat Maps Awards

Continuing my series of articles looking at shot locations I thought I would bring together a few team heatmaps for the inaugural Heatmap Awards

First of all, for those unfamiliar, here is how I’m defining the different zones where shots are taken from:

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West Ham

In one of my very first articles I looked at the “West Ham Phenomenon” where they had much more of their shots from great shot locations that we might have expected.
Well it seems that their obsession with shots from great positions goes even farther than I thought.

Unbelievably, West Ham has the highest proportion of their shots from the prime position than ANY of the other teams in the Big 5 leagues (England, Spain, Germany, Italy and France).

West Hame best prime

At 47.6% of their shots from prime locations they are almost 2% clear of the team that has the second most proportion of shots from prime spots, Bayern Munich.  That really takes some comprehending and I think we can put that down to “AllardyceBall”.

I expect that some readers will be suggesting that a large proportion of those attempts from prime positions are from headers, primarily from Andy Carroll.

I had another look at the figures, this time excluding headers and they no longer sit at the top of the table across the Big 5 leagues.  That accolade goes to PSG (35.2%).  However, they only slip to third in the EPL table at just 1% below the figures returned by the two Manchester clubs.  Again, I’d imagine this is a much more impressive figure than most readers would have expected to see.

Arsenal

I’ll shift the focus to Arsenal, where I found some numbers that suggests that the reputation Arsenal have earned for walking the ball into the net has been earned.

Arsenal best poor

Just 0.7% of Arsenal’s shots (inc headers) are struck from what I have termed as very poor locations.  In a “normal” team that would be indicative of serious shot discipline as they do not take wasteful shots.  However, perhaps in Arsenal’s case some more variety may be helpful to them, nevertheless, the Gunners do deserve credit for the careful consideration of their shots.
The next placed teams in the Big 5 leagues had a figure of 1.4% of their shots originating from very poor positions.

Pescara

The Italian side Pescara is included in this article for the wrong reasons.  They had the worst shooting locations out of all the teams in the Big 5 leagues.

Pescara

45% of Pescara’s shots came from the two worst zones on the pitch.  It therefore shouldn’t come as a surprise to too many readers that they were cast well adrift at the bottom of Serie A this season.
For information, Lazio and Rayo Vallecano also featured at the top of this particular unattractive list.

Bayern Munich

In contrast to Pescara if we look at the two best zones (prime and secondary) combined, we find that the Bavarian giants had the best shot positions out of all the teams in my data set.

Bayern

Almost 79% of Bayern’s shots came from the two most favourable shooting zones.  On this measure they just pipped Man United (78%) and PSG (77%) across the 5 leagues.

Shots on Target Across the Big 5 Leagues

As tends to happens to me upon reading interesting articles, when I came across this article in relation to shots on target from Ted Knutson yesterday my mind starting to think about what I could prove or disprove.

In the data that Ted analysed, shots in the English Premier League on target were much rare than the other 3 leagues he looked at.  I wondered (as he did) why that might be, and also if that is the case in the data that I have painstakingly gathered.

For those unaware, thanks to Squawka, I have recorded each shot that was taken in the Big 5 leagues for the season just ended.  The Big 5 leagues are the top divisions in England, Spain, France, Germany and Italy.

Shots on Target

The following table shows the proportion of shots that were on target in each league for the 2012/13 season:

leagues

So my findings pretty much tally with those of Ted.  The German Bundesliga has the greatest proportion of shots that are within the frame of the goal at 35% and England bring up the rear with less than 32% of the shots taken in the Premier League being on target.

Possible Explanations

In order to try to explain why different leagues would have different percentage of shots on target when they play the same game I came up with the following possible explanations:

  1. The players in the EPL are less skilful or accurate than those found in the other four leagues
  2. On average, shots are taken from worse locations in the Premier League than in other leagues
  3. There is greater defensive pressure on the ball in England than is found in the other leagues

Those possible explanations don’t exactly break new ground, in fact Mr Knutson came up with those  exact same explanations in this article posted on Thursday afternoon.

I’m afraid that as a data collector I can’t really offer up anything substantive in terms of proving or disproving the first possible explanation, however, hopefully I (and my data set) can be useful in trying to see if explanations 2 and 3 have any merit.

Shooting Locations

One aspect of the game that I have plenty of data on is shooting positions, so I’m able to investigate the shot locations for each league.
Before I do that I’ll explain a little about how I’m going to present the data.

Following some feedback on how I was assigning “poor” and “good” shooting locations in previous articles I have come up with the following graphical representation method.

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Shooting locations have been divided into 4 groupings as shown above.  I am not going to tell the readers what the expected percentage of shots on target should be for each grouping, but hopefully the above will be a useful way to compare the shooting locations across each of the leagues.  In summary, the farther away from the goal the location the poorer the shooting location becomes.

For each country I will also include a much more visually impressive heatmap than the ones I have created.  These snazzy heatmaps where created for me by my friend @cchappas. The two styles of viz work well together, as one gives detailed information whilst the other provides a much easier “at a glance” representation of the data.

Germany

Germany

Bundesliga

36% of shots in the Bundesliga this season were taken from the central belt within the penalty area, although I haven’t noted it on the image, 14% of shots were taken from within the 6 yard box.  30% were taken from slightly worse, but still promising, locations and finally just 5% of shots were taken from what I have described as very poor positions, ie far out or beyond the edges of the penalty area.

How does the Bundesliga compare with the others?

Spain

Spain

PrimeraDivision

The shot spread in La Liga wasn’t very different to those seen in Germany, at 34% Spain had slightly less shots from the prime central positions.  Those few missing percent of shots that came from the central area in Germany were pushed out slightly to the Secondary positions, but other than that it was pretty much as we were.

France

France

Ligue1

The trend of the slight decrease in shots from Position A continues when we look at the French Ligue 1, this is witnessed by the increase to 5% for shots coming from the worst locations.  Indeed you can see that the shot distribution is much more even in France than in the leagues we have looked at so far.

Italy

Italy

SerieA

I am looking at the leagues in descending order of shots that end up on target and the amount of shots taken from prime positions in Serie A is now down to 31%.  It’s comforting when the results of a test match the hypothesis that we set out with, ie that the decrease in shots on target can be (at least) attributable to the shot locations.
With that in mind, and the fact that the EPL has the lowest percentage of shots on target I wonder will the amount of shots from prime locations in the Premier League fall much below 30%?

England

Englans

PremierLeague

Wow.  What has happened here?

36% of shots in the Premier League came from the best positions.  Not only that, but within that figure 15% of shots were from inside the 6 yard box – none of the other leagues posted a higher figure that that.  Contrary to what I had expected to see the Premier League actually had shots from better positions than the other leagues.

The amount of shots from the secondary position is also exceptionally high at 35%.  This leaves just 29% of shots being struck from the two worst zones in the EPL, the next lowest figure was 33%!!
The Premier League clubs will undoubtedly be happy to learn that the players on their books take shots from what appears to be the best positions on the pitch, certainly compared to the other leagues in my data set.

Does that mean that my hypothesis of shot location acting as an explanatory variable for explaining the percentage of shots on target in the bin?

I don’t think so.  Excluding England, there certainly appeared to be a clear pattern where the proportion of shots on target was correlated with the amount of shots that were taken from the more favourable shooting locations.
But, given the amount of shots in my data set I don’t think we can ignore the findings from the Premier League.  Can we come up with a logical explanation for these findings?

Defensive Pressure

If you’re still with me, you may recall that the third and final possible explanation I had in my locker to explain why different leagues had a different amount of shots on target was that of defensive pressure.
Presently, and it is a great bugbear of the analytics community, there is no (or virtually no) data available which measures defensive pressure.
However, prompted by a few articles by Footballfactman such as this one I realised that we could probably use the amount of blocks as a proxy for defensive pressure.  After all, a shot can’t be blocked if the striker isn’t being closed down at the moment they shoot for goal.

I looked at the proportion of shots that were blocked this season in each of the Big 5 leagues, and the findings make interesting reading.

Blocked2

Perhaps as expected, the Premier League is well clear of the other four leagues in terms of the amount of shots that are blocked.  I think we could conclude that there is, indeed, much more pressure on the shooting players in England than there are in the other countries.  Perhaps this is because teams tend to play with a higher line in the Continental leagues and allow much more space in behind them, but whatever the explanation the effect is certainly there.

In my opinion the amount of pressure on the ball in England is even more stark than the above table shows.

Remember that shots in the Premier League came from better positions on average than the other leagues.  In an earlier article where I looked at where blocked shots originated from there was a clear pattern where the amount of shots which were blocked decreased the closer the shots were to the goal.  Earlier on in this article we ascertained that the top flight English teams actually had a greater proportion of their shots from those prime locations where blocked shots should have been less of an occurrence.
England has 42% of shots from outside the box in the secondary and marginal position zones – and this is where blocked shots occur at the highest rate.  However, Spain also has 42%, France 41% and Italy a massive 48% from these zones.

This, combined with the fact that England has more shots than the other leagues from prime positions where blocks are rarer suggests to me that the pressure on both the ball and the attacking players in the Premier League is not even fully captured in the above table of blocked shots.
I think this is a very important point for anyone who attempts to undertake analysis of the different leagues.

Summary

We confirmed that different leagues do have different proportions of shots are on target.  There are several different possible explanations for why this could be the case.
I didn’t attempt to see whether the first explanation, ie players having different skill levels was plausible, but I think I was able to ascertain that the shot location is an important aspect in explaining whether a shot is going to be on target or not.

However, the third possible explanation, that of defensive pressure seemed to have an even stronger explanatory impact than that of shot location and this was starkly seen in the Premier League where the amount of blocks was far in excess of what we might have expected, especially given the shot positions.

The Smart and Accurate Shooting of Sau

Following on from this article that MixedkNuts wrote on Serie A talent I thought it worth taking a cursory look at the shooting figures posted by Cagliari’s Marco Sau this season.

As Ted points out in his article he has some really admirable goals and shots on target numbers.

Here are his shot and goal charts (exc penalties) for the 2012/13 season:
Sau

Look at how tidy his shooting locations are. The vast majority of the shots are from central and / or fairly close in and his goal conversion ratio is also something to admire.
He seems to have the ideal mix of being a smartshooter and well as a sharpshooter.

So although most readers of this article won’t have heard of Sau before this afternoon, I’d have to agree with Ted in his summation of “This guy is special and could be a good goalscorer pretty much anywhere.”