Val Ball and stats

[Derek Hardballs]

Sorry, do you think someone sitting in a room is deciding what xG each shot is?

No I was asking a question and software is only as good as the person coding it. Doesn’t mean it’s bullet proof as a method to determine whether a team has played well.

It's not to determine whether a team has player well, it's an indicator of how good are the chances that they've had in a game.

xG takes a database of millions of shots and looks at historical chances that are from the same position/same speed of pass prior to the chance/whether its a header or shot as the current chance and sees how often chances that are identical or as close to identical as possible resulted in a goal (broadly speaking, there's some smoothing involved too but that will change the result by 0.001 type magnitudes).

The point is it's based upon whether shots have gone in in the past in identical/similar situations. What judges whether it is a good chance or not is what has happened over millions of shots in the past. It's as watertight as it can possibly be, and it's very simple coding that can be verified by the most junior of data scientists with the same data.

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In what World did Hugill's stats get him a job, unless it was purely how far he runs in games?! Seriously. What stats does he have that mean he should be playing anywhere? Oliver Burke is another prime example. Lots of mediocre players keep getting massive deals, but their stats surely would not warrant it. Then again that's why I write code and am not a massively rich football manager. It's the one job where you can be pretty shit and still get more highly paid work.

Well it's certainly not his xG stats is it? Maybe people were using their eyes instead and coming to the wrong conclusion that he could be a productive goal scoring striker

Well we shall see if those same attacking players create and convert more chances now we have a change of manager won’t we.

Who said anything about the manager?

We could convert every single shot we have from now until the end of the season and it wouldn't change the fact that we were failing to convert chances earlier in the season?

Pts accrued is the only stat that counts in the end. Hard luck stories about how many chances we missed no matter how they are packaged are ultimately meaningless. If the new manager doesn’t create as many chances, doesn’t get in as many stat friendly areas of the pitch on average but we score more goals and accrue more pts than Val ball, then his imo over reliance on stats to determine tactics will seem like a reasonable conclusion to why he struggled and left the club.

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I read it as another post deriding the over-use of stats in the game.  Personally; I think stats should be used to validate the opinions of experts, not shape them.

This.

Contrary to what Derek may believe I don't tend to look at any stats after a game.

But when there is a debate about why we score so few goals, I might look at some stats to see if the opinion I have formed from watching games is justified.

Ans maybe, just maybe, if someone had looked at the playing records of some of our recruits prior to them joining us, we might not have such a goal shy squad.

 I said it’s a tool to use but should not be a determining factor of a manager. Management isn’t just the interpretation of data. It should not underpin every decision on recruitment and tactics for example.

[MassDebater]

What I'm always amazed by is that a lot of people who use stats, especially xG, to make out Six's side were doing OK, are also the same people that say Slav's team limped over the line and he was a shit manager. Even though the stats don't say it...

I honestly do not remember a single argument based on xG when Slav or even BFS for that matter were in charge. Yet the xG stat has been around for a good amount of time.

[Shabby Russian]

What I'm always amazed by is that a lot of people who use stats, especially xG, to make out Six's side were doing OK, are also the same people that say Slav's team limped over the line and he was a shit manager. Even though the stats don't say it...

I honestly do not remember a single argument based on xG when Slav or even BFS for that matter were in charge. Yet the xG stat has been around for a good amount of time.

I'll give you 2 stats that showed conclusively that Bilic's team declined in form towards the end of the season.

1 51 points in the first half of the season, 32 points in the second.

2 In the first half of the season we only failed to score in 1 game. In the second half we failed to score in 7 games.

Limping over the line is not a phrase I ever used, but by many measure the second half of that season was not as good as the first half. Which is the wrong way round.