Magpie Circle Altrincham Preview

[magpie_mania]

I base my fair score stats on the xG data I have available to me. The club will have much greater detail in their data than I do to deduce their fair score.

Essentially it’s a metric used to determine performance vs results and to identify where improvements can be made to make sure good performances are always rewarded.

I mentioned on the Notts County Talk pod that Neal Ardley actually recorded 7 points more than expected based on performances this season. That would suggest we overachieved in several games and that this is not actually sustainable.

If you look at Ian Burchnall’s first 8 games he’s recorded 7 points but performances actually suggest that should have been 15 points. He’s been let down by poor finishing, defensive mistakes and some fantastic saves by opposition goal keepers. The margins are so small which is why data plays such a big part in the modern game.

This is a genuine question - at the end of the season - which would we prefer?

Over-achieving in the xG data and getting promoted.
Under-achieving in the xG data and missing out.

I suppose that over a season, like penalties etc it should even itself out - I'm sure there must be data available to give results. It does seem though that often teams get promoted by winning games when they don't play well.

We obviously need to over-achieve when xG is low and achieve when it's good. I agree though that relying on the first over a long period is simply not sustainable. But is 7 points really that much? It's only winning 2 and drawing 1 you didn't deserve to based on 'fair play'

[ncfcog]

This is a genuine question - at the end of the season - which would we prefer?

Over-achieving in the xG data and getting promoted.
Under-achieving in the xG data and missing out.

I suppose that over a season, like penalties etc it should even itself out - I'm sure there must be data available to give results. It does seem though that often teams get promoted by winning games when they don't play well.

We obviously need to over-achieve when xG is low and achieve when it's good. I agree though that relying on the first over a long period is simply not sustainable. But is 7 points really that much? It's only winning 2 and drawing 1 you didn't deserve to based on 'fair play'

Don’t shoot the messenger

Joking aside you are of course right, as a fan I just want to see us win games regardless of performance. However, as I’m now entrenched in the football statistics world I do now view the game in a slightly different way.

Ultimately xG and other fair score metrics are essentially there to assist managers and coaches in identifying areas that require improvement, How many people on here during their working lives have had to make changes to the way they work because their company have been recording key performance indicators (KPIs)? It’s the same thing.

One thing is obvious though, performances from an attacking perspective have without doubt improved, unfortunately we need to start taking our chances, do that and the defensive issues won’t matter so much and will become fewer as time progresses.

[jacobncfc]

This is a genuine question - at the end of the season - which would we prefer?

Over-achieving in the xG data and getting promoted.
Under-achieving in the xG data and missing out.

I suppose that over a season, like penalties etc it should even itself out - I'm sure there must be data available to give results.'

The first, definitely. But the theory is that it’s quite hard to do either over a 40+ game season because it’s a big sample size over which things will ‘even themselves out’. We’re quite a good example of this theory playing out - we’re about where we should be over the course of the season, despite bits where we’ve been a bit lucky and overperformed and bits where we’ve been a bit unlucky and underperformed.

There are always outliers, Brighton in the Premier League this season are the best example of a team wildly underperforming their xG, but in general the final table will look pretty similar to the xG one.

What it does allow you to do is identify trends during the season and work out whether you’re on the right track or not.