Expected goals

[Diable Rouge]

The stat appears to be somewhat Duckworth-Lewis in terms of how it is calculated, in terms of distance, clear paths to goal, angular trajectory, etc. It may well be useful in predicting match outcomes, team efficiency, etc, but given that the ratio of shots on target converted into goals serves a similar purpose, are expected goals entirely necessary?

http://www.telegraph.co.uk/football/...remier-league/

[Kevin S]

Well, to go all Jeff Stelling on you, the only stats that are entirely necessary are goals and points. But folk will doubtless be shocked if I say that yes, I think this is quite a useful stat in evaluating a team's performance.

The conversion ratio tells you how well a team is taking their chances.
xG tells you about the quality of the chances they are creating, irrespective of whether or not they are scored.
The opposition's xG in a match is your xGA, and that tells you the quality of the chances you are allowing against you, irrespective of whether or not they are scored.

It's easy to rack up 25 shots on goal if they are all from 40 yards out or an impossible angle, but it doesn't suggest you've played very well. If you have a high xG and a low xGA then it shows that, if chances were taken in line with expectations, you would be winning those games. OK, so in reality you passed up a high percentage chance and they scored from a lower percentage chance but in terms of how well you were playing as a team, on the whole, you were doing well.

Most explanations of this then give the example of Juventus' Serie A season in 2015/16. Here's our thread on that season. They started the season very slowly, dropping points all over the place. But you'll see even on the thread that we expected them to close the gap.

xG and xGA from that season are the stats that gave objective weight to the idea that Juventus would win the league. They were creating far more score-able chances than their opponents - 'outplaying them' if you like. They were just doing shit like this, against Inter:

I decided that Khedira's miss was worthy of preserving for posterity in GIF form. We can all appreciate a Juve fail like this, I'm sure.



(Apologies for adding "KHEDIRA" underneath.)

Once regression to the mean kicked in, and chances were being taken in line with expectation (at both ends) they ended up winning 15 Serie A games in a row and cruising to the title.

[EIM]

It's a load of wank.

[Kevin S]

Excellent, I was hoping for a following post like that. I think we've completed the debate now.

[andrew7610]

Having weighed up both sides of the argument, as eloquently put forward by the correspondents above, I am firmly sided with EIM on this.

It adds as little to my viewing pleasure on MOTD as those wanky handshake goal celebrations do.

[EIM]

I mean, I'm sure it has its uses, and boffins can extrapolate all kinds of shit from it, but it says nothing to me about my life.

The spreadsheetisation of football, which I blame entirely on Football Manager and Fantasy Football, sucks all the fun out of the game. It's like looking at a painting and wondering what the hex colour codes are.

[EIM]

Wanky handshakes and daft haircuts though. I live for this shit. Viva Paul Pogba. Long live Jesse Lingard. Down with angry internet Dads.

[E10 Rifle]

I'm sure it's interesting to some people, but not to me. And wouldn't cheer up my post-match mood one iota were I aware of 'impressive' expected goal stats in a game we lost.

[Toby Gymshorts]

Down with angry internet Dads.

I have never fathered a child, nor do I plan to. To whose mast do I nail my colours as regards being angry about things on the internet?

[Various Artist]

It's kind of interesting, but I think this (even more than EIM's opening gambit in this thread) sums it up the best for me:

The spreadsheetisation of football [...] sucks all the fun out of the game. It's like looking at a painting and wondering what the hex colour codes are.

For example that article quotes a STATS research paper that sounds like one of the most spirit-sucking, joy-crushing things imaginable – "The Leicester City Fairytale?": Utilizing New Soccer Analytics Tools to Compare Performance in the 15/16 & 16/17 EPL Seasons. For fuck's sake.

[Wouter D]

Oh, please. Researchers I am collaborating with are waaaay ahead of the curve here, using Bayesian networks to find:

- "The most anomalous midfielder is Scott Sinclair"
- "Edin Dzeko [...] is a highly anomalous striker"
- "For the single feature score, Robin van Persie is recognized as a clear striker because of the ShotsOnTarget feature."

From the paper "Model-based Outlier Detection for Object-Relational Data", accessible here.

Mining results based on individual referees and teams is research in progress. Preliminary conclusions: Peter Walton and Sunderland are weird.

[Gerontophile]

Down with angry internet Dads.

And "Daddies"?

[Gangster Octopus]

Saucey...

[Gerontophile]

There was a thing in the Graun about the topic in question. I almost read it.

[Gerontophile]

Saucey...

I do like an 'E'.

[Kevin S]

It's kind of interesting, but I think this (even more than EIM's opening gambit in this thread) sums it up the best for me:For example that article quotes a STATS research paper that sounds like one of the most spirit-sucking, joy-crushing things imaginable – "The Leicester City Fairytale?": Utilizing New Soccer Analytics Tools to Compare Performance in the 15/16 & 16/17 EPL Seasons. For fuck's sake.

And yet you have how many Xpert Eleven teams?

[Antepli Ejderha]

And yet you have how many Xpert Eleven teams?

Kevin S, you are always going to be Statto and Kevchenko which therefore means you started all of this.

[Gerontophile]

I dunno why, but I always thought that 'Kevchenko' was Scottish?

[Kevin S]

Haha, well, I occasionally daydream of moving to a Hebridean island if that helps. I think Katie Morag's dad has this whole 'life' idea sussed out.

Edit, er, sorry, that's quite the thread tangent there.

[San Bernardhinault]

The Sabermetricisation of sport is fine for backroom boffins and intellectuals like Sam Alladyce and Ryan Giggs to use as analysis, but it's soul destroying for spectators where sport is most joyous because it's unpredictable.

[ursus arctos]

I've never understood that particular point of view, but to each its own.

Statto was/is a Leeds supporter.

[The Awesome Berbaslug!!!]

Well if football punditry and all discussions of football are going to be endlessly backed into Scoreboard cuntishness, you're going to have things like this. Like everything else bad about the modern world, this is mostly jose mourinho's fault

[Antepli Ejderha]

I've never understood that particular point of view, but to each its own.

Statto was/is a Leeds supporter.

How the fuck do you know all of this? I went to the same school as him and his brother.

[ursus arctos]

I've been around for a long time, AE

[Antepli Ejderha]

But even so UA, I thought this was such a cultural reference. Chapeau to you sir, you are an OTF legend.

Did you ever watch any of the show btw?