xG Goal Expectancy Rate (a mentalist RAWK statistical spinoff thread) ft Babu of RAWK fame

Discussion in 'Football Forum' started by Harold_Giles, Oct 2, 2017.

  1. Oct 2, 2017
    #1

    Harold_Giles Full Member

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    Babu:
    Everything is fine.

    Their avg. xG is 1.5 higher than of their opponent.

    I wonder if this xG thingy factors in shit defenders?
  2. Oct 2, 2017
    #2

    MaxiPaxi likes to shove his mum's boiled eggs up his rectum

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    My word. He'd melt my fecking head if he was on here spouting all that bollocks.
  3. Oct 2, 2017
    #3

    P-Nut0712 fan of well-known French footballer Fabinho

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    https://understat.com/team/Liverpool/2017

    Not that it needed clarifying, but they've been closer to matching the opposition than being that far ahead of them for most of the season anyway. See the xG and xGa at the bottom for the average over the season.
  4. Oct 2, 2017
    #4

    MaxiPaxi likes to shove his mum's boiled eggs up his rectum

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    What the feck is xG? Sounds something like Klopp would drop before heading out to the touchline.
  5. Oct 2, 2017
    #5

    MaxiPaxi likes to shove his mum's boiled eggs up his rectum

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    Another clinker from Baba Yega:

    What a load of fecking drivel. fecking mentalist.

    Edit: He doesn't actually compare him to Xavi but he does mention Lallana in the same breath as Isco, De Bruyne, Messi and Silva.
    Last edited: Oct 2, 2017
  6. Oct 2, 2017
    #6

    Shane88 Full Member

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    What in the name of Christ are those crop circle stat things?
  7. Oct 2, 2017
    #7

    FlawlessThaw most 'know it all' poster

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    If I posted on RAWK, it would be the first time I'd ever use "tl;dr"
  8. Oct 2, 2017
    #8

    MaxiPaxi likes to shove his mum's boiled eggs up his rectum

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    I've no idea. It's way over my head anyway. One thing I know, though - OX is fecking shite!
  9. Oct 2, 2017
    #9

    P-Nut0712 fan of well-known French footballer Fabinho

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    I got halfway through that before realising wtf I was doing with my life.
  10. Oct 3, 2017
    #10

    Suedesi Full Member

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    Expected Goals is computed to turn each goal scoring attempt into a number between 0 and 1, representing the odds of that attempt producing a goal.

    The easiest attempt to explain is a penalty.

    Typically, penalties are awarded around 0.75 ExpG, based on historic conversion rate. A penalty is the easiest attempt to classify, since it’s a situation isolated from play, with a standard spot for taking it.

    You can expand the number of situations and run separate regression models for other situations such as open play shots, headers, direct free-kicks, corners, throw-ins, fast breaks, rebounds from a keeper save, rebounds from the woodwork etc.

    Essentially you can use a database (Opta) that will allow you hundreds of thousands of simulations to come up with an Expected Goal value for each situation.

    And in a low scoring game like football, you can have a much xG than the opponent and not win. That's why in turn statistical models are not necessarily accurate predictors of match outcomes.
    Last edited: Oct 3, 2017
  11. Oct 3, 2017
    #11

    Suedesi Full Member

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    Don't confuse poor language skills with being erratic. There's not a lot of wrong with what he says.
  12. Oct 3, 2017
    #12

    SmashedHombre Memberus Anonymous & Legendus

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    What? Football is still a game, right?
  13. Oct 3, 2017
    #13

    P-Nut0712 fan of well-known French footballer Fabinho

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    Been considering explaining this for a long while but I only ever see it mentioned in the rawk thread so people will ignore it and still use it to laugh at Liverpool, which after all is what the thread is for.
  14. Oct 3, 2017
    #14

    montpelier Full Member

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    I've gone right off the xG, the game's moved on

    Last edited: Oct 3, 2017
  15. Oct 3, 2017
    #16

    Mciahel Goodman Worst Werewolf Player of All Times

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    All of that xG stuff is complete nonsense.
  16. Oct 3, 2017
    #17

    King Kendrick Full Member

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    Not to derail the thread, but it also fails to take into account the player itself. A header from Mata, a header from Lukaku/Ibra, even if taken from the same spot, are bound to have different expectations of results.
  17. Oct 3, 2017
    #18

    montpelier Full Member

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    I think they do want to start doing that, :)

    <ponders throw-in distribution map & xTI data>
  18. Oct 3, 2017
    #19

    Suedesi Full Member

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    Yes, that's true, a chance is a chance.

    In your system when you take into account the player itself, then every goal scoring chance presented to Welbeck is a zero, even if he's facing an open net. And then every shot on goal towards let's say Karius is a sitter because well he is a bad keeper in your view. It doesn't work that way. You evaluate the chance itself using parameters such as distance to goal, the angle, the pressure on the ball, the movement of the ball, the crowd in front of the ball etc, regardless of the players involved.

    So essentially a great chance is a great chance regardless if it falls to Ronaldo or Crouch. Then, world class players perform well above the xG, the average ones perform exactly at the xG, and the poor ones perform below xG.
    Last edited: Oct 3, 2017
  19. Oct 3, 2017
    #20

    King Kendrick Full Member

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    But then that ruins the purpose of the argument doesn't it? You can't bang on about we had 6 xG, but if they all fall to the feet of Smalling and he takes a shot each time, its not really 6 xG is it?
  20. Oct 3, 2017
    #21

    Suedesi Full Member

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    Anyways, there's value to statistical models and regressions in soccer, but not as much as in baseball or basketball, because in a low scoring sport like footie you can end up with huge variances which can distort data, and an unsophisticated observer will misrepresent or misinterpret the output.
  21. Oct 3, 2017
    #22

    Suedesi Full Member

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    Erm, yes it is, that's why Lukaku is better than Smalling at putting away chances.
    Or if you create a chance against Burnley and the same exact chance against Bayern Munich, you apply the same finish, the Burnley one goes in, the Bayern one is saved by Neuer... would you blame the finishing? Or would you say the keeper made a great save against a shot that normally goes in.
  22. Oct 3, 2017
    #22

    Mciahel Goodman Worst Werewolf Player of All Times

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    Thread made by moving posts from RAWK.

    Though, on a separate note, if any other posts derail the rawk thread, I might just lump them in here too. I'd like to understand this xG thing because I don't have a clue at the moment. Seems like an over-complicated way of making yourself feel better for not scoring because statistically you should have scored. It's creating a new reality almost. I could have it all wrong, of course.
  23. Oct 3, 2017
    #23

    montpelier Full Member

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  24. Oct 3, 2017
    #24

    RedCurry Full Member

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    I love how Liverpool fans and their manager are arguing about "creating" loads of chances and then go on to talk about that one chance that Sturridge should have apparently put away. That chance was entirely created by an shocking defensive mistake and had nothing to do with Liverpool's buildup play.
  25. Oct 3, 2017
    #25

    Mciahel Goodman Worst Werewolf Player of All Times

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    @marukomu would have burned the RAWK thread to the ground. Had to move this shit here asap :lol:
  26. Oct 3, 2017
    #26

    montpelier Full Member

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    I'm not sure you can add them together to try & say the team deserved 3 goals because of a load of imagined / measured fractions of goals that haven't been scored.
  27. Oct 3, 2017
    #27

    UnrelatedPsuedo I pity the poor fool who stinks like I do!

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    I think it does take into account the player now. As of this season.

    Though doing so would make the prediction less reliable as they'd have tiny data sets to work from.

    Lots of Opta Analysis is snake oil though. They preach in absolute but record in vagaries.
  28. Oct 3, 2017
    #28

    Banat New Member

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    So is this Babu Yagu actually PhaseOfPlay in disguise? Very similar style, and RAWK and their mods are well-known for having multiple profiles.
    He made some brave predictions about us finishing 6. again, Ox setting the league alight and of course Lukaku flopping.
    Looks like he will be hounded by Christmas, just like the fellow PoP :lol:
  29. Oct 3, 2017
    #29

    King Kendrick Full Member

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    No I understand what you're saying, but it's more to the point of the end product. To me it's just talking in circles.

    Of course there are going to be different variables in every situation, but if someone says that "oh we should have won that game because we had 6 xG and they had .5," and the final score is 1-0 to the opposition, you have to look at the context of those numbers. It's why I brought up the Smalling example, and it's the same with your example. There is context and noise behind those numbers that maybe are accounted for, but I fail to see.
  30. Oct 3, 2017
    #30

    adexkola American Arse

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  31. Oct 3, 2017
    #31

    AR87 Full Member

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    It's pretty foolish to use on a single match basis IMO. It's a statistic that's best over a larger sample.

    In Liverpool's case, if they keep underperforming xG in attack as they have this season that indicates a desperate need for a clinical finisher to be added. This was an issue for United last year and one that adding a player clinical like Lukaku has helped, without even accounting for the impact he's had on our overall play.
  32. Oct 3, 2017
    #32

    King Kendrick Full Member

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    You seen the RAWK thread with Babu? Lol
  33. Oct 3, 2017
    #33

    Moonred Full Member

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    Wow a thread about Baba yoghurt’s erudition.
  34. Oct 3, 2017
    #34

    Irrational. Full Member

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    xG is football analysis gone bonkers.
  35. Oct 3, 2017
    #35

    shabadu84 Mint? Berry?

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    I think essentially it's an attempt at quantifying and visualizing performance beyond counting statistics by applying quality as a factor. Sometimes that can reveal things you didn't know, which can help address weaknesses or identify talent. We already do some of this ourselves when we say things like "half-chances" or "missing a sitter". This is a good read on it.

    http://www.telegraph.co.uk/football...does-show-man-city-should-win-premier-league/

    Often just tells us what we already know:

    But I think there's something potentially useful to it, even if that is just highlighting to Liverpool that they're even more hopeless than they think.
  36. Oct 3, 2017
    #36

    nikineil New Member

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  37. Oct 3, 2017
    #37

    clarkydaz Full Member

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    called the 80s?
  38. Oct 3, 2017
    #38

    P-Nut0712 fan of well-known French footballer Fabinho

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    It actually isn't as bad as people make out. It's a detailed way of the old saying managers 'I'll start to worry if we're not making chances'
  39. Oct 3, 2017
    #39

    Suedesi Full Member

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    xG attempts to quantify the number of chances and quality of chances one creates against the other team.

    But, I do agree with you that context is important.

    eg. we're leading 3-0, we drop a gear in intensity in the last 10 minutes, the opposition creates 4 chances without scoring.
    xG would be useless in this context, because the game is practically over and racking up chances in the end without scoring is kinda meaningless. Maybe if the opposition scored, the manager would have made some tactical changes, subs, etc to tighten up. As it is, he's just letting the game peter out.

    on the other hand, if this was a hard fought 0-0 with both teams going at it until the end, yes xG would be a useful illustrative tool.
  40. Oct 3, 2017
    #40

    Stobzilla Official Team Perv

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