xG - hype or valuable stat?

[Ram-Alf]

On 13/02/2024 at 11:39, David said:

Absolute nonsense stat that needs to get in the bin.

Would that be the small bin a the X large bin😁

[Ram-Alf]

On 13/02/2024 at 14:52, richinspain said:

"Statistics are like a mini skirt, very nice to look at but hide what's really important" - Jimmy Sirrel.

...he should know, He signed some right cnuts ☺️

[Comrade 86]

1 hour ago, Ram-Alf said:

...he should know, He signed some right cnuts ☺️

[ap04]

16 hours ago, Gee SCREAMER !! said:

We'd probably have won that by more if we'd stepped it up rather than soak it up for 20 minutes

Exactly, it's not enough that we scored with our second, third and fourth clear chances, which would normally take 11 of these and happens 5% of the time, we were due to score even more! Just about every time we get near it shall be a goal (whilst at the same time our opponents miss all of theirs). Are you for real or just trolling everyone?

[Duracell]

xG needs a rebrand. It doesn't mean "how many you should have scored" - it's a metric of how many shots were close to goal.

If you see a team with loads of shots and low xG, you can tell that it was a side struggling to break into the final third and taking fanciful shots at goal.

If you see a high xG and no goals scored, you know a team's been wasteful.

I don't see what's hipster or controversial about that.

[Gee SCREAMER !!]

7 hours ago, ap04 said:

Exactly, it's not enough that we scored with our second, third and fourth clear chances, which would normally take 11 of these and happens 5% of the time, we were due to score even more! Just about every time we get near it shall be a goal (whilst at the same time our opponents miss all of theirs). Are you for real or just trolling everyone?

I'm saying that your stat bothering is more painful than VAR.  Crack on though, someone might be interested..

[Grimbeard]

On 13/02/2024 at 13:06, IlsonDerby said:

Surely moved past smarmy pundits giving it the ‘the only stat that matters is the goals scored stat’ large. 
 

For once, the pundits (smarmy or otherwise) are correct.

[IlsonDerby]

12 hours ago, Grimbeard said:

For once, the pundits (smarmy or otherwise) are correct.

For an individual match? Yes. 
 

If you’re looking for patterns more longer term ie - is this good run sustainable or is it relying on clinical finishing that is unlikely to keep up its current rate? 
 

alternatively after a bad run of results : are we that bad or have we genuinely been quite unfortunate ie keepers playing blinders against us or strikers hitting worldies. 
 

performances always tend to regress to what the underlying stats are saying. 

[roboto]

17 hours ago, Duracell said:

xG needs a rebrand. It doesn't mean "how many you should have scored" - it's a metric of how many shots were close to goal.

If you see a team with loads of shots and low xG, you can tell that it was a side struggling to break into the final third and taking fanciful shots at goal.

If you see a high xG and no goals scored, you know a team's been wasteful.

I don't see what's hipster or controversial about that.

It's hipster because it's been coined and stylised as 'xG' instead of 'Expected Goals'

It's controversial because people think that by having this stat, that all the old stats are being discredited, which isn't the case.

Give it a few more seasons and people will have moved on to moan about something else. Probably xSB (aka Expected Sin Bin minutes) where players are ranked on their their time off the pitch and how much stress it causes on their team during the season 🙂 

[ap04]

On 14/02/2024 at 10:46, MadAmster said:

we set out with a game plan, executed it very well and won 3-0.

This is perceived this way because of how the goals went on the day. In fact we were more superior on Saturday albeit at home, but because we scored just 1 from nearly as many openings and also conceded from far fewer everyone was moaning.

On 13/02/2024 at 11:57, Ian Buxton's Bat said:

Our XG for is 1.46 per game and we're scoring 1.74 per game.........outperforming it with only one striker available

Our XG against is 1.07 per game and we're conceding 0.94 per game........again goalies and defenders must be doing a lot right

This is a common misconception often repeated in the media, the above usually means overrated, lucky and not evened out rather than a trait. This is the essence of xG, taking the small sample problem out of it.

Ideally in assessing a side's prospects you want to have been "underperforming" as it means results are about to improve.

On 14/02/2024 at 11:40, nottingram said:

A team can score early (ish) and then let the other team rack up low quality chances and they end up “losing” on xG.

The whole point of sitting back is that it usually makes it harder for the opposition to create clear chances (lower probability overall to score ie. xG). Else it wouldn't be done.

Sometimes it also leads to more openings on the break.

[Ghost of Clough]

50 minutes ago, ap04 said:

This is perceived this way because of how the goals went on the day. In fact we were more superior on Saturday albeit at home, but because we scored just 1 from nearly as many openings and also conceded from far fewer everyone was moaning.

This is a common misconception often repeated in the media, the above usually means overrated, lucky and not evened out rather than a trait. This is the essence of xG, taking the small sample problem out of it.

Ideally in assessing a side's prospects you want to have been "underperforming" as it means results are about to improve.

The whole point of sitting back is that it usually makes it harder for the opposition to create clear chances (lower probability overall to score ie. xG). Else it wouldn't be done.

Sometimes it also leads to more openings on the break.

It could be either, which is why you only use it as part of an analysis. If someone like Harry Kane has outperformed his xG by 50% for 10 consecutive seasons, it's because he's a good finisher, not because he's been lucky for 10 years in a row.

However, Nick Blackman may hit a 6 month purple path where everything goes in and his actual goals vs xG is through the roof. In this case, it's not due to being a good finisher, he's just in a good bit of form.

Stats like xG and xA are based on averages. Some players are above average, others are below average.

[ap04]

22 minutes ago, Ghost of Clough said:

It could be either, which is why you only use it as part of an analysis. If someone like Harry Kane has outperformed his xG by 50% for 10 consecutive seasons, it's because he's a good finisher, not because he's been lucky for 10 years in a row.

On a site like understat you can see 2 things:

First, how much most players' goals to xG yo-yo even between seasons never mind briefer periods. It's not enough data. Haaland couldn't buy a goal the other month, same as Kane now. Mane Vardy and Aubameyang were top scorers in between 'underperforming'.

Second, that even on entire career average hardly anyone outperforms their xG by much let alone 50%, even the perceived very best marksmen in recent history:

Ronaldo 229->234
Messi 220->253
Lewandowski 278->271
Mbappe 163->185
Kane 201->234
Benzema 169->166
Haaland 100->114
Salah 176->186
Suarez 166->179
Mane 117->118
Aguero 127->133
Lukaku 147->155
Immobile 165->178

This is less than 10%, or 1 or 2 goals a year, it's nothing.

So 'clinical' is a bit of a myth, it's more things like positioning and good teammates that make the difference.

[Ghost of Clough]

1 hour ago, ap04 said:

On a site like understat you can see 2 things:

First, how much most players' goals to xG yo-yo even between seasons never mind briefer periods. It's not enough data. Haaland couldn't buy a goal the other month, same as Kane now. Mane Vardy and Aubameyang were top scorers in between 'underperforming'.

Second, that even on entire career average hardly anyone outperforms their xG by much let alone 50%, even the perceived very best marksmen in recent history:

Ronaldo 229->234
Messi 220->253
Lewandowski 278->271
Mbappe 163->185
Kane 201->234
Benzema 169->166
Haaland 100->114
Salah 176->186
Suarez 166->179
Mane 117->118
Aguero 127->133
Lukaku 147->155
Immobile 165->178

This is less than 10%, or 1 or 2 goals a year, it's nothing.

So 'clinical' is a bit of a myth, it's more things like positioning and good teammates that make the difference.

Using your source, Son's averaged 37% more goal than his xG over his career, and is currently 61% up for this season.

[Dean (hick) Saunders]

I’m indifferent to the topic and part of me wants to understand it better, but the other part can’t be arsed as I’m 50 and have many better things to do with my time.

Also I have got to a life stage where I only care about the Derby County games and don’t really have any interest in football apart from us. Especially premier fing league. Not watched a PL match (even on tv) since we were relegated in “that season”.

Edited February 16 by Dean (hick) Saunders

[Comrade 86]

17 minutes ago, Dean (hick) Saunders said:

I’m indifferent to the topic and part of me wants to understand it better, but the other part can’t be arsed as I’m 50 and have many better things to do with my time.

Not nearly as complicated as some seem intent on making out to be and it's in no way critical to most fan's enjoyment. Likewise, 'not getting it' does not in any way lessen your understanding of the game IMO. I think it's something of interest principally for football stattos, clubs and on both sides of the betting markets and it's interesting that many big clubs now have in-house teams developing and running their own versions of xG. Personally, I think that's indicative of football teams increasingly looking for incremental gains and an enhanced focus on identifying any less obvious weaknesses in opposing teams as well as their own playing roster.

[DarkFruitsRam7]

On 13/02/2024 at 06:01, nottingram said:

Think I’ve said it before but if it was called something like “chance quality” instead of expected goals then you’d have a lot less people poo-pooing it for whatever reason they do.

It’s not the be all and end all but can add context if you want it to. Does make me laugh when people will say it’s meaningless and then happily sit there quoting shots or shots on target.

This 1000 times over

[Day]

I’ve had a think about this, opened myself up to the counter arguments and I’ve come to the conclusion I am still correct.

It’s a nonsense stat.

However I would concede that rebranding it as chances created cC, or even opportunities, I would have less issues with it.

This idea that a player is in this position on the pitch, he’s “expected” to score is as I say nonsense and disrespectful to defenders and keepers.

Now if you’re telling me, that having a player in this position on the pitch has a chance/opportunity to take a shot and score, absolutely I can buy into that.

Look at a penalty, dead ball situation with a 1 on 1, great chance/opportunity to score, however I watched Mbappe have a penalty save the other day. Didn’t take it. That’s football.

The X is terrible branding, as it is for the rebranding of Twitter. 

Also, as a stat, you shouldn’t have variations depending on what website you’re reading.

[Returning ram]

Still don't get the debate, their own website states it's not accurate. 

Expected goals predicts the correct home team result 66% of the time and away results 58% of the time. This is slightly better than shots on target on the away results and slightly worse on the home results.

[Dean (hick) Saunders]

Anyway. What is XB (expected beers 🍺) stats for me after the match today?

Will it be score/result dependent? Does consolation equal more beer than celebration?

I’ll report back later..

Edited February 17 by Dean (hick) Saunders

[richinspain]

1 hour ago, David said:

I’ve had a think about this, opened myself up to the counter arguments and I’ve come to the conclusion I am still correct.

Said the great man himself 

*each one can make their own minds up as to who the great man is