Nations · 6 editions · 17 countries in the long run · 95/96–25/26

The same five questions, asked of 6 nations.

Each edition — Czechia, Denmark, England, Spain, Germany and Norway — measures its pool the same way: how many players reach the strongest leagues per million, how many minutes the home league gives its own under-21s, when the first move abroad comes, how strong the home league is, and what the national-team squad is built from. Side by side, the numbers say where a nation is out of line. The decomposition says which mechanism carries most of a gap. The long run says when each country's presence in the Big-5 changed level. None of it proves a cause; the page says where that line is.

What to take from it

1

Czechia is the one small nation whose Big-5 presence fell and has not come back.

It rose in 00/01 (×1.66) and fell in 14/15 (×0.58); 10 players with 450+ Big-5 minutes now against 26 at the 07/08 peak. At the 07/08 peak the nation's Big-5 players had a median age of 28; in the 14/15 fall season it was 32 and no debutant arrived — a generation retired and what followed was thinner.

Croatia fell too (03/04) and came back 11 seasons later; Norway fell too (04/05) and came back 17 seasons later. Every other small peer's later step is a rise.

2

Two problems at once, not one: which mechanism carries the gap depends on the peer.

Against Norway home-league strength carries 73 % of a 7.0-per-million gap; against Denmark youth minutes at home carries 72 % of a 10.2-per-million gap. They add up rather than compete: a league that gives its young few minutes and is weak besides loses on both counts.

3

The trend runs the wrong way: Czechia's own under-21s went from 10 % to 6 % of home-league minutes in 6 seasons.

Over the same seasons Norway 8 % → 11 % and +2.7 per million in the Big-5; Denmark 16 % → 15 % and +2.3 per million in the Big-5; Czechia -0.1 per million. Across the 16 covered leagues the change in youth minutes and the change in Big-5 presence lean the same way — a weak signal with the right sign, not a law.

4

Where the mistake shows: Czechia is out of line on the first rung — minutes for its own under-21s and the timing of the first move.

Out of line: minutes for its own under-21s at home: 6.4 % of league minutes and 1.1 regular under-21 starters per club, last among the peers (Denmark 15.3 %; Denmark 2.5 starters per club); the first move abroad at a median 24 (Norway 22); the exporters move at 22–23; how many leave at all: 32 first moves in the covered seasons (Denmark 112); how many clubs the exports leave from: 54 % of the 48 players who went from the home league to a top-9 league since 20/21 left from Sparta Prague or Slavia Prague (Norway: 22 % from its top two, 54 exports in all).

Not the problem: the home league itself: multiplier ×0.43, 2 of 9 among the peers; how its exports fare: a median 50 % of their club's minutes, 3 of 9.

What the peers show is reachable: two regular under-21 starters per club (from 1.1) — Denmark 2.5, Croatia 2.3, Hungary 2.2 already do; the first move at 22–23, not 24 — the route the peers that grew use; more of them, not better ones: the exports that do go hold their place.

The four numbers to watch every summer: under-21 share, regular under-21 starters per club, age of the first move, first Big-5 seasons. None of this is a proven cause; it is where the nation is out of line with the peers that grew, on the mechanisms the gap decomposition weighs most.

5

Can a reform cause it? The data can follow 2 documented cases, and only as a sequence.

Germany after its DFB/DFL academy licensing (01/02): its own under-21s' share of Bundesliga minutes went from 5 % to 11 % by 09/10 but is 6 % now — the turn did not hold. England after its Elite Player Performance Plan (12/13): its own under-21s' share of Premier League minutes went from 3 % to 6 % by 19/20 but is 3 % now — the turn did not hold. A sequence in one country against none in another is the strongest thing this data can say; it is not a counterfactual. Read as a heuristic: minutes for the young at home are the lever a federation holds, the effect is counted in seasons, and a weaker league yields less from it.

Each statement is written from the numbers below at build time, so it moves when they do; the evidence and its limits follow in order.

A · side by side

Where Czechia is out of line, in the numbers every edition shares.

How to read it: each edition's own headline numbers, last completed season; the brightest value in a row is the best of the editions.

what the rows mean

Per million counts players with a season in the nine strongest leagues. For a nation whose home league is one of them (England, Germany, Spain) that includes the home league — which is why the rank is against the nation's own peer set, not across editions. Under-21 minutes and regular starters are measured in the home league; the first move abroad is the median age at a player's first season in a headline league; the squad row is the share of the last full national-team squad playing in a top-9 league.

B · why a nation lags — youth, or something else

Czechia against Norway, home-league strength carries 73 % of a 7.0-per-million gap; against Denmark, youth minutes at home carries 72 % of a 10.2-per-million gap.

how the decomposition works, and what it cannot say

Each edition's own decomposition: a ridge regression of players-per-million on youth share, home-league strength and the age of the first move across that edition's eight or nine peers, then a Oaxaca–Blinder-style accounting of the gap to each contrast ((Oaxaca, 1973); (Blinder, 1973)). A channel's share is how much of the gap that mechanism accounts for at the fitted coefficients; the channels can sum to more than the gap and the residual takes the rest. It says which measured mechanism carries a gap. It does not say what would happen if the youth share rose — that needs change over time within a country.

Six seasons at home — the change the cross-section cannot see

How to read it: the share of each home league's minutes played by its own under-21s, every complete season the pipeline covers; the chips choose the countries (they also drive the long-run charts below).

How to read it: each country's change in that share against its change in Big-5 presence over the same seasons — the within-country picture, one point per country, 16 countries and six seasons: a direction, not an estimate.

The cross-section behind it

How to read it: one point per country (16), last completed season; pick the mechanism on the x-axis. The dashed line is a plain fit for the direction only — the three mechanisms move together, so a stronger league keeps more of its young players and exports them later.

C · the long run, 95/96–25/26

Who fell, who rose, and when — every country's presence in the Big-5, with two dated steps each.

How to read it: players with 450+ minutes in a Big-5 league that season, per million; a diamond is a dated step (hover for size and certainty); a dashed rule is a documented reform — a date, not a cause.

how we know, and the two reform dates

FBref's season tables for the Premier League, Serie A, La Liga, Bundesliga and Ligue 1, from the first season all five are covered. Each country gets the report's two-step change-point model ((Adams and MacKay, 2007), in a batch, two-break setting). For a Big-5 nation the count includes its own league, so its series is mostly about how international that league became. Reform markers: Germany 01/02, DFB/DFL academy licensing (Honigstein, 2015); England 12/13, Elite Player Performance Plan (Premier League, 2011). Whether a series moved because of a reform is not something a marker can tell; the honest reading is the timing, against countries that did nothing.

every country's steps as a table

"Shape vs CZE" is the correlation of the per-million series with Czechia's — the countries whose long run looks most like Czechia's are the analogies worth reading, whatever their level. A second step that is a rise is a recovery after a plateau; Czechia's second step is the one fall among the small nations.

When a country's players arrive, and how young

How to read it: the same countries as above; age at a player's first Big-5 season of 450+ minutes (three-season median, because a small nation sends two or three a year), or the under-23 share of the nation's Big-5 minutes, or the count of first seasons. Did a recovery come with younger arrivals? Did Czechia's arrivals get older around its fall?

Youth minutes in the Big-5 leagues themselves

How to read it: the share of each Big-5 league's minutes played by its own under-21s (age at 1 July), season by season — the one youth series the data carries back this far. Germany after 2001/02 is the case to read first.

D · what this can and cannot say