The largest single-club contingent in each World Cup squad at kick-off, and whether packing a squad with team-mates actually helps. Club = the club listed on the Wikipedia squad roster. Cache-only.
Bloc size and over-performance are barely related: Spearman ρ = -0.10 (by count) / -0.13 (by share of squad), n = 240. The theory that a core of club-mates lifts a national team is not supported — the largest blocs belong to weaker sides built around one dominant domestic club (Qatar's Al-Sadd, Saudi Arabia's Al-Hilal), which if anything drags the correlation negative.
| # | Squad | Club | Bloc | % of squad | Over/under |
|---|---|---|---|---|---|
| 1 | 🇶🇦 Qatar 2022 | Al-Sadd | 13/26 | 50% | -0.21 |
| 2 | 🇸🇦 Saudi Arabia 2022 | Al-Hilal | 12/26 | 46% | -0.05 |
| 3 | 🇨🇿 Czech Republic 2026 | Slavia Prague | 10/26 | 38% | -0.36 |
| 4 | 🇨🇷 Costa Rica 2002 | Alajuelense | 9/23 | 39% | -0.29 |
| 5 | 🇸🇦 Saudi Arabia 2018 | Al Hilal | 9/23 | 39% | -0.08 |
| 6 | 🇨🇷 Costa Rica 2006 | Saprissa | 8/23 | 35% | -0.15 |
| 7 | 🇸🇦 Saudi Arabia 2006 | Al Hilal | 8/23 | 35% | -0.04 |
| 8 | 🇬🇷 Greece 2010 | Panathinaikos | 8/23 | 35% | -0.21 |
| 9 | 🇪🇸 Spain 2022 | Barcelona | 8/26 | 31% | -0.20 |
| 10 | 🇪🇬 Egypt 2026 | Al Ahly | 8/26 | 31% | +0.40 |
| 11 | 🇿🇦 South Africa 2026 | Mamelodi Sundowns | 8/26 | 31% | +0.28 |
| 12 | 🇪🇸 Spain 2026 | Barcelona | 8/26 | 31% | +0.09 |
| 13 | 🇵🇹 Portugal 2002 | Sporting CP | 7/23 | 30% | -0.66 |
| 14 | 🇸🇦 Saudi Arabia 2002 | Al Hilal | 7/23 | 30% | -0.11 |
| 15 | 🇺🇦 Ukraine 2006 | Dynamo Kyiv | 7/23 | 30% | +0.38 |
| 16 | 🇩🇪 Germany 2010 | Bayern Munich | 7/23 | 30% | +0.29 |
| 17 | 🇰🇵 North Korea 2010 | April 25 | 7/23 | 30% | -0.02 |
| 18 | 🇪🇸 Spain 2010 | Barcelona | 7/23 | 30% | +0.14 |
| 19 | 🇩🇪 Germany 2014 | Bayern Munich | 7/23 | 30% | +0.26 |
| 20 | 🇩🇪 Germany 2018 | Bayern Munich | 7/23 | 30% | -0.76 |
| # | Club | Player-tournaments |
|---|---|---|
| 1 | Bayern Munich | 87 |
| 2 | Barcelona | 86 |
| 3 | Real Madrid | 79 |
| 4 | Arsenal | 77 |
| 5 | Manchester United | 77 |
| 6 | Manchester City | 74 |
| 7 | Chelsea | 71 |
| 8 | Juventus | 69 |
| 9 | Liverpool | 58 |
| 10 | Paris Saint-Germain | 57 |
| 11 | Tottenham Hotspur | 54 |
| 12 | Milan | 52 |
| 13 | Atlético Madrid | 51 |
| 14 | Inter Milan | 50 |
| 15 | Borussia Dortmund | 48 |
| 16 | Ajax | 44 |
| 17 | Bayer Leverkusen | 40 |
| 18 | Benfica | 38 |
| 19 | Roma | 37 |
| 20 | Monaco | 37 |