Quique Setien

Porque

Senior Member
Trying to decipher how or why we actually utilized sub's and tried a system with a front 2 once LaLiga is gone.

It is like we agreed to thro... Oh wait, I better stop.
 

LeeRomeno

Active member
In many ways yesterdays game felt very similar to last game with Valverde (the Supercopa one). I think we played really well there as well, were very unlucky not to win, but felt like some sort of burden had been lifted from coach and he actually decided to play in a bold way.
Got similar vibes yesterday, so much talk about him being replaced, all the issues with Griez/Messi and weird press-conferences. Maybe it was just this "fuck it" moment, where you feel like you have nothing to lose and try smth not safe.
 

Birdy

Senior Member
I have no clue what XG is, except what you have told me right now.

So, I won't analyze those stats since I don't know how they work, what are the limitations and towards which type of matches/teams/number of shots is that system biased.

I guess that XG, like all stats has some limitations and things which you don't see on stats.

XG is the best metric we have so far to determine how good a chance (a final attempt taken) created by a team is.
This is done my measuring a number of factors, like distance from goal, position of the GK, players in front of the ball, speed of the ball before taking the attempt, angle etc

For example a shot taken with an xG of 0.01 is not the best attempt to score a goal: it goes in only 1 out of a 100 times. On the contrary a shot taken with an xG of 0.3 is a quite good chance: it goes in 3 out of 10 times. To get an idea of how the percentage goes: a PK has an xG of 0.75

Now, if you see the xG score line of a game (which is the outcome of adding up all the attempts, excluding penalties, and their respective xG counts to determine a scoreline for both sides) you get a sense of how 'well' both teams performed, especially if you combine it with an xG shot map. 'Well' means here how effective (irrespective of playing style).
Low xG means inability to create danger, inability to translate possession into meaningful chances, while high xG means the contrary.

Discrepancies between an xG scoreline and the actual scoreline happen for three main reasons:
i) Luck (big part in football)
ii) Referee decisions (a penalty gives a very probable goal to a team with 0.75 chance)
iii) Individual over/under-performance on both ends

Regarding iii, for example Liverpool's underlying numbers at the end of 17-18 season were not far from their underlying numbers of 18-19, but the inclusion of Alisson in the place of Karius made a significant change. They managed to get scorelines that reflected their defensive performance better, because the GK was not conceding chances with low xG.
Likewise, having Messi upfront gives a team the luxury to turn frequently attempts of low xG (for example free kicks from outside the box with 0.05 and below) into goals.

A good team offensively = a team that does not rely on individuals to turn low xG attempts into goals, but provides them the opportunity to finish off high xG attempts
A good team defensively = a team that does not give away significant chances to the opposition (attempts of decent and high xG) relying on the GK to save them.

If you calculate points gained after every fixture based on xG scoreline and not the actual scoreline, you can create a table of 'what it would have been had the actual scorelines resembled the effectiveness of the team'

There you see that EV record is pretty horrible. There are many sites/resources you can look at, i will give you one: According to understat:
The 17/18 xG tally of Barca was 79.44 points, 13 and more less than the actual 93. While Real Madrid's was almost the same 79.99, 4 more than the actual 76 they got
The 18/19 xG tally of Barca was 73.96 points, 13 again less that the actual 87.

So, we see that even his best 17/18 season was based largely on Messi over-performing upfront to turn insignificant chances into goals, and Ter Stegen over-performing at the back to save the team's ass from malfunctioning defensive reactions.
 
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BBZ8800

Senior Member
Birdy, ok.

After reading this, I can see one flaw already.

Our game is designed around Messi.
And for example, if Barca creates 5 chances.
And if RM or Inter create the same number of chances, we will have the same XG, right?

But our results will be better.
Due to luck?
No.

Because we have Messi and Suarez shooting.
Inter has Lautaro who can't score.
RM has Vinicius who gets in 5 chances but can't score.

So, our XG would be higher with Ansu or Braithwaite, but our results will be higher with Suarez.

Some players get into more chances but are bad finishers.
Some don't get into too many chances, but they score a lot.

About a low XG og EV's Barca: our team is not as bad as XG shows.
We just don't shoot too much.
Instead of shooting, we pass to Messi.
So, we have low amount of chances, but we seem to win more than we should, right?

When I posted stats, people often told me: stats can't tell the whole story.

I have spent only 2 minutes thinking about XG and you can already find flaws, as explained above.
 

BBZ8800

Senior Member
Lol, 100% of the stats you post frequently are as flawed if not more than what Birdy posted.

And when you don't like my flawed stats, you say it.
Yet, when they fit you, you like it. Isn't it?

Our style of play (Messipendencia) and a lack of pacey wingers who get into a lot of chances will cause a lower XG.
It doesn't mean that we are as shit as XG suggests.

I will take 7:15 shots at Barca:Real match as long as Messi has 3 attempts, Suarez 3 attempts and Benzema 5 and Vinicius 7.
That's an easy 3:1 win for us, in spite of Xg saying that Real should have won.

XG doesn't understand who is Vinicius Jr/Benzema and who is Messi when they shoot from inside of a box.
 

serghei

Senior Member
And when you don't like my flawed stats, you say it.
Yet, when they fit you, you like it. Isn't it?

Our style of play (Messipendencia) and a lack of pacey wingers who get into a lot of chances will cause a lower XG.
It doesn't mean that we are as shit as XG suggests.

I will take 7:15 shots at Barca:Real match as long as Messi has 3 attempts, Suarez 3 attempts and Benzema 5 and Vinicius 7.
That's an easy 3:1 win for us, in spite of Xg saying that Real should have won.

XG doesn't understand who is Vinicius Jr/Benzema and who is Messi when they shoot from inside of a box.

No, when I use stats I use it to prove the point you just made. They are flawed instruments most of the time.

Barca play everything through Messi. It is a tactic of the team to sacrifice better passing (thus reducing their xG) to play Messi in a worse position, because Messi in a worse position can still do some magic.
 

KingLeo10

Senior Member
@BBZ8800 Although I haven't seen xG's methodology, one possible and immediate way (if this isn't already accounted for) is to incorporate prior probabilities (e.g. probability of Messi having scored in the past from a given set of conditions like distance from goal, players in front of him, GK positioning; this would be much lower with a Vinicius or Benzema for the same shot parameters for example) with the general predictions based on observed shot parameters, the latter of which I believe is what xG does right now.

Stats aren't flawed by nature IMO. They're flawed when people want to make interpretations based on them that the statistic wasn't designed to answer or is limited in answering.
 

Richard.H

Senior Member
I think he will get exposed in the CL. The team still looks incredibly vulnerable to a counter attack. Most CL sides counter attack endlessly. Can't rely on our slow back 4 and mid to get back.
 

serghei

Senior Member
I think he will get exposed in the CL. The team still looks incredibly vulnerable to a counter attack. Most CL sides counter attack endlessly. Can't rely on our slow back 4 and mid to get back.

Maybe we'll get lucky. A great QF draw and we can end up in the SF. Anything can happen in 90 mins.
 

serghei

Senior Member
He win next 6 games (4 Liga, 2 CL) and I think he will stay next year.

Makes little difference now. It's clear he has accepted he doesn't have too much power in the team. At beast we'll look like a more watchable late Valverde Barcelona.

Maybe the veterans will get re-motivated after this failure of a season. And might push for 1 more La Liga.
 

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