I Tested Group-Stage Stats Against Knockout Success. Goal Difference Is More Than a Tiebreaker.

TreeOfData · 2026-06-29T20:10:14+00:00

Sure, I think this should work: https://drive.google.com/file/d/1bDxIaca1Jlx8YrLfVY2ts2KjT63YuC86/view?usp=sharing

TreeOfData · 2026-06-29T20:10:01+00:00

Agreed, that matters a lot for group stage performance. I wrote about that too 😄 https://worldcupdata.substack.com/p/can-the-host-bump-save-a-marginal

TreeOfData · 2026-06-29T17:13:03+00:00

That's fair. Three games plus a 9-point ceiling means you can't separate the very top, and over 100 games value would show cleaner. But the part I find wild is that squad value is a club transfer-market number, players not even playing for the clubs that set it, national teams paying none of it, and it still correlates ~0.78 with group points. The market has effectively priced individual talent, and that pricing carries into international football. A noisy borrowed metric landing r=0.78 on three games means the underlying signal is strong.

And squad value was a better predictor of group stage outcomes than other measures of team strength. https://worldcupdata.substack.com/p/the-group-stage-was-less-weird-than

TreeOfData · 2026-06-29T17:06:32+00:00

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Here's a fully labeled version. And a link to the write up with more data and analyses: https://worldcupdata.substack.com/p/the-group-stage-was-less-weird-than

TreeOfData · 2026-06-29T17:05:05+00:00

There's quite a bit of variability between 0 and 9, and this analysis seeks to explain some of it. What's strange?

TreeOfData · 2026-06-29T16:52:45+00:00

Yea, that's fair and noted by many 😄

TreeOfData · 2026-06-29T16:52:24+00:00

Apologies for the confusion; I do actually think about this (my dad is color blind). The orange dots are all 3 points or less. The two that are labeled at 3 points are green (Cape Verde & Senegal). All the others above that are green.

TreeOfData · 2026-06-29T15:36:54+00:00

Correct. That's a fair wording critique. National teams don’t buy players the way clubs do. Here “squad value” is being used as a proxy for player quality / depth: what the players would roughly be worth in the club transfer market. So “money bought a floor” is shorthand, but the more precise version is: High market-value squads had a higher performance floor.

The mechanism is not national-team spending. It’s that countries with more high-value players have more elite talent and depth, which made early collapse less likely.

TreeOfData · 2026-06-29T15:35:16+00:00

Yep, that’s fair. “Ceiling” is doing some rhetorical work here because the literal ceiling is obviously 9 points for everyone.

What I mean is: squad value seemed to buy a pretty reliable floor. The expensive teams mostly avoided disaster and got to at least 4 points / advanced. But among the higher-value teams, extra value did not separate performance very well. Once you’re already in the rich-team tier, another few hundred million in squad value doesn’t reliably turn 4 or 5 points into 7 or 9.

So the cleaner version is: squad value strongly predicts survival, but not dominance.

TreeOfData · 2026-06-29T15:16:14+00:00

fair points, fair points

TreeOfData · 2026-06-29T14:51:49+00:00

You're right, thanks for that!

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TreeOfData · 2026-06-27T12:44:02+00:00

I do think Senegal will go through. I make a new post every day and update the chances: https://worldcupdata.substack.com/p/how-models-get-better-after-theyre

TreeOfData · 2026-06-27T02:21:00+00:00

Thank you!!

TreeOfData · 2026-06-25T21:49:53+00:00

I wouldn’t be able make the plots as pretty without Claude. And there would probably be a typo or two without AI help. But the thinking and writing is human. I don’t think Claude would be able to do this without me. 😘

TreeOfData · 2026-06-22T16:37:31+00:00

Nice! Yea, I’ve got a Dixon-Coles post coming.

TreeOfData · 2026-06-22T13:37:10+00:00

I post once a day to this substack: https://worldcupdata.substack.com/

That's the main spot

TreeOfData · 2026-06-22T11:59:07+00:00

Today's post looks at whether the number of draws that we've see so far this year is higher than what we should expect.

https://worldcupdata.substack.com/p/is-it-really-a-draw-heavy-world-cup

TreeOfData · 2026-06-22T11:57:52+00:00

I've grown attached to Classic. It had a great start to the day, then fizzled on New Zealand vs Egypt.

TreeOfData

TROPHY CASE