CL Round: Newcastle - Barca 1-2

[draconifire]

The Premtard have been glazing Pedri since the game. Lol

It's like Neanderthals watching humans light a fire.

 

[FC B]

Struggled offensively big time in the first half and also didn't create much before Rashy's first goal but mostly after his second but missed chances way too easily.

This can be put on Lamine's absence which led Flick to play Raph on the right wing which didn't pay off at all but gladly Rash made quite a debut in CL for Barca with his two goals.

All in all it was a great away win on a difficult ground where not long ago Liverpool struggled to win and won much harder than Barca with a very late goal.

 

[Birdy]

I agree with you - to a point. The problem is xG still has flaws (needs to measure game state because teams will build xG when 3-0 down and the other team takes foot off gas etc, and should take into account who's shooting - obviously Haaland is more likely to score than Ake). To be fair those new game state graphs seem to be trying to remedy this somewhat.

Also, as I said, I like it as a stat in principle (though I agree it doesn't necessarily mean you dominated the game if you win it, just created better chances) - as I said my problem is how the numbers are sometimes calculated. I gave two examples above where the xG of Spurs and Man City in games against Man United just did not seem right. If I thought it was very accurate I would trust it more. But how did City have less than 2 xG against United last week and how did Spurs only have 0.8 xG that night they scored four? In both games those teams had objectively good chances that fell to good finishers.

The problem for me isn't the idea of the stat - it's that how it is calculated and some of the context it neglects can make it seem more flawed than it could be.

@Birdy what do you think? Are these thoughts fair?

Generally, it is as Temptation says.

There are things to improve for the future. For instance, a differentiated xG that takes into account the personal efficiency (based on the history of strikes from same positions) of each player is something to look forward in the future.

As for the game states, yes that is true. But that is the job of tactical analyst to take into account in a piece, and has no bearing on the method used for calculating xG

Finally, I would say there are different xG calculation models. No all are equally good. For instnace, understat is one of the worst in the industry. Opta and Statsbomb are top

PS: Let me add this again for people (like Serghei and others) that keep repeating this on purpose:
Total xG of a game says nothing, when you don't look specifically at the composition of that aggregate.
You always have to look at xG shotmap and look at the big (or at least semi-big) chances to draw conclusions.
That's over 0.3 xG or around that number.

 

[JamDav1982]

Said this before but know of EPL clubs banning the talk of xG as it lacks too much and saw it as a distraction as to how games actually went at times.

You can make a world class move open a team up and miss strikers toes by a whisker for a tap and in nothing registered.

It is useful in ways to get some idea of dominance in shots made/chances but not something clubs use really at all.

 

[serghei]

I am pissed at myself.

EDIT : it says 3 Clasicos without Messi.

2019 5-1 at Camp.

Barca never played at Santiago without Messi.

2016. 4-0 with Ney, Suarez, and Iniesta running the show. Messi came in at 3-0 or 4-0.

 

[Maradona37]

Generally, it is as Temptation says.

There are things to improve for the future. For instance, a differentiated xG that takes into account the personal efficiency (based on the history of strikes from same positions) of each player is something to look forward in the future.

As for the game states, yes that is true. But that is the job of tactical analyst to take into account in a piece, and has no bearing on the method used for calculating xG

Finally, I would say there are different xG calculation models. No all are equally good. For instnace, understat is one of the worst in the industry. Opta and Statsbomb are top

PS: Let me add this again for people (like Serghei and others) that keep repeating this on purpose:
Total xG of a game says nothing, when you don't look specifically at the composition of that aggregate.
You always have to look at xG shotmap and look at the big (or at least semi-big) chances to draw conclusions.
That's over 0.3 xG or around that number.

Thanks, lots of that makes sense. And yeah, you give good explanations for most of the flaws I pointed out. Good point too that cumulative xG is more misleading and it's more about the bigger chances. I assume a lot of nothing chances would often accumulate a bigger xG than two very very good chances. So like you say it's more about xG for the individual chances.

I have some other thoughts I might put down on paper at some point.

Just one thing - you didn't reply to what I said about that Spurs game and the City game at the weekend, both against United (as examples).

I will just take the game at the weekend as it is fresh in the memory - I assume you watched it, or at least have seen highlights and saw the copious one on ones City either converted or missed.

How can xG come to the conclusion that their expected goals was fewer than 2? Haaland scored two chances that were very good chances, for starters. He also missed pretty much a sitter off the post (admittedly someone, I think it was Luke Shaw, was in the way putting him off and he tried to avoid him hence the miss) and Reijnders was through on goal too. That allied to a few other decent chances, and Foden's goal might have been low xG but still was a fairly good chance - how does xG come to the conclusion it was fewer than 2 xG?

What I am asking is, when you see the xG figures (for the sites you reference as good), do you trust them implicilty? Or do you ask yourself if it reflects what you seen in the game with your eyes (if you watched the game or seen the highlights).

My problem isn't with xG as a use, my problem is that some of the figures the models come up with don't seem to match what I watched. Admittedly I could be being biased in the entire eye test, but I think anyone who watched that game at the weekend would say an xG of 3 for City would be fair - not less than 2 xG

 

[Maradona37]

Said this before but know of EPL clubs banning the talk of xG as it lacks too much and saw it as a distraction as to how games actually went at times.

You can make a world class move open a team up and miss strikers toes by a whisker for a tap and in nothing registered.

It is useful in ways to get some idea of dominance in shots made/chances but not something clubs use really at all.

Just seen this.

Yeah it lacks some context. I was gonna make a post about how other stats lack context too, I might when I can be bothered. But you know when a pass is completed - it's a cold hard fact even if it doesn't measure how progressive the pass is, if it was the correct pass (was a better one on?), if it had good weighting, if it was into the path of the receiving player or if he had to recover it as it was passed poorly. You need eye test for this. But ultimately, a pass completed is a cold hard fact.

But how do you measure the quality of a chance? Yes you can make attempts to, and it is a worthy effort, but there will always be flaws as the quality of a chance is subjective and subject to variables (quality of finisher and goalkeeper amongst others) and therefore it's more subjective to measure than other more cold stats.

'You can make a world class move open a team up and miss strikers toes by a whisker for a tap and in nothing registered'

Yeah made the same point myself. If a player doesn't get a shot on goal then it doesn't come up as xG so it doesn't measure just missed connections. Remember Gazza against Germany at Euro 96? He was a whisker away from putting them in the final. If that was now it wouldn't come up because he just didn't reach it.

If you get what I mean.

I am not putting down xG as totally useless, that is not my point. But some people (I don't mean anyone on here) try to use it as proof that one team deserves to win over another. Tempt himself, an advocate of it, even says it doesn't measure who dominated the game, just who had the best chances. Having more or better chances doesn't automatically mean you were the better team, but you see people on Twitter etc posting xG stats as if it proves one team was unlucky to lose and other other lucky to win, and it really isn't as simple as that.

it's a worthwhile tool, but it does contain flaws. And needs to be used in conjunction with other tools and the eye test too.

 

[JerseyAddict]

That was an intelligent play from Raph... Waitng in his half for ball to be sent

 

[Birdy]

Thanks, lots of that makes sense. And yeah, you give good explanations for most of the flaws I pointed out. Good point too that cumulative xG is more misleading and it's more about the bigger chances. I assume a lot of nothing chances would often accumulate a bigger xG than two very very good chances. So like you say it's more about xG for the individual chances.

I have some other thoughts I might put down on paper at some point.

Just one thing - you didn't reply to what I said about that Spurs game and the City game at the weekend, both against United (as examples).

I will just take the game at the weekend as it is fresh in the memory - I assume you watched it, or at least have seen highlights and saw the copious one on ones City either converted or missed.

How can xG come to the conclusion that their expected goals was fewer than 2? Haaland scored two chances that were very good chances, for starters. He also missed pretty much a sitter off the post (admittedly someone, I think it was Luke Shaw, was in the way putting him off and he tried to avoid him hence the miss) and Reijnders was through on goal too. That allied to a few other decent chances, and Foden's goal might have been low xG but still was a fairly good chance - how does xG come to the conclusion it was fewer than 2 xG?

What I am asking is, when you see the xG figures (for the sites you reference as good), do you trust them implicilty? Or do you ask yourself if it reflects what you seen in the game with your eyes (if you watched the game or seen the highlights).

My problem isn't with xG as a use, my problem is that some of the figures the models come up with don't seem to match what I watched. Admittedly I could be being biased in the entire eye test, but I think anyone who watched that game at the weekend would say an xG of 3 for City would be fair - not less than 2 xG

Long story short:
xG of 1 does not equal one good chance.
If you think that an xG of 0.3-0.4 translates to an actual sitter, you put that into different perspective

 

[Maradona37]

Long story short:
xG of 1 does not equal one good chance.
If you think that an xG of 0.3-0.4 translates to an actual sitter, you put that into different perspective

The way I thought it worked was a sitter would be like 0.8, is that not true?

I do get your point, but it doesn't seem to account for games where both teams seem to have an equal amount of good or slim chances, one team has an xG of almost three higher.

Anyway not too bothered - it's a decent tool but obviously has some flaws too and is in its infancy and yet to be (almost) perfected. It must be used in addition to other stats and the eye test. I hope you think that's a fair statement.

 

[Birdy]

The way I thought it worked was a sitter would be like 0.8, is that not true?

I do get your point, but it doesn't seem to account for games where both teams seem to have an equal amount of good or slim chances, one team has an xG of almost three higher.

Anyway not too bothered - it's a decent tool but obviously has some flaws too and is in its infancy and yet to be (almost) perfected. It must be used in addition to other stats and the eye test. I hope you think that's a fair statement.

No unfortunately. xG 0.8 is practically an empty net.
The fact that many people had missed (and will continue to miss) such empty nets makes it impossible to have it at 1 or close because of how math works in statistical probabilities

Then it is also the model. Trust Opta and Statsbomb

 

[Andresito]

Penalty is almost 0.8 no?

 

[Maradona37]

No unfortunately. xG 0.8 is practically an empty net.
The fact that many people had missed (and will continue to miss) such empty nets makes it impossible to have it at 1 or close because of how math works in statistical probabilities

Then it is also the model. Trust Opta and Statsbomb

Fair enough. I guess that makes sense - if plenty players miss sitters, the model must account for that. Makes you wonder how any teams build xGs of over 3 and 4 at all.

Maybe you'll say it is my anti Man United bias, but United seem to always do well in this stat, even in games I don't think they create particularly good chances. Equally, I see teams create good chances against them (like the night Spurs scored four, allowing one was from a corner) and they only have an xG of 0.78 lol.

I think it's a good tool and has its uses, but has some flaws as Jam points out and the numbers arrived at need to be questioned more at times rather than believing them on face value.

Just my take.