https://www.robsiegwart.com/2026-07-12T00:00:00-05:002026-07-12T00:00:00-05:002026-07-12T00:00:00-05:00Rob Siegwarttag:www.robsiegwart.com,2026-07-12:/world-cup-teams-by-club-composition.html

<p class="first last">Analyzing club concentration and domestic retention across 2026 World Cup rosters.</p>

<p>A recent World Cup conversation got me thinking about how national teams at the 2026 World Cup differ in their club composition, that is, the club teams that supply the players on their roster.</p> <p>My initial hunch was that teams drawing more from one or two clubs (for example, Spain utilizing Barcelona players) might fare better due to pre-existing player familiarity. Of course, that logic depends on the quality of that club — the national team would only be as good as the club team it drew from. To test this, team quality variances would have to be normalized.</p> <p>Nevertheless, out of curiosity I pulled the rosters for the 2026 World Cup <a class="reference external" href="https://en.wikipedia.org/wiki/2026_FIFA_World_Cup_squads">as posted on Wikipedia</a> and created some derivative charts and statistics:</p> <ul class="simple"> <li><a class="reference internal" href="#club-concentration-metrics">Club Concentration Metrics</a> (Table)</li> <li><a class="reference internal" href="#club-concentration-by-national-team">Club Concentration by National Team</a> (Graph)</li> <li><a class="reference internal" href="#top-feeder-leagues">Top Feeder Leagues</a> (Graph)</li> <li><a class="reference internal" href="#club-count-distribution">Club Count Distribution</a> (Graph)</li> <li><a class="reference internal" href="#top-feeder-clubs-by-player-count">Top Feeder Clubs by Player Count</a> (Graph)</li> </ul> <p>HHI is a metric used here and refers to the &quot;Herfindahl-Hirschman Index&quot; which is calculated by squaring the share of players for each club and then summing. Squaring makes dominant clubs push the index up faster. For example,</p> <blockquote> <p>A squad split 10/6/4/3/2/1 across six clubs gives:</p> <p><cite>(10/26)² + (6/26)² + (4/26)² + (3/26)² + (2/26)² + (1/26)² ≈ 0.246</cite></p> </blockquote> <div class="section" id="takeaways"> <h2>Takeaways</h2> <ul class="simple"> <li><strong>Talent supply is heavily concentrated at the top.</strong> The big 5 leagues (the top leagues of England, Germany, Spain, France, and Italy) account for roughly 39% of all players. At the club level, Manchester City, Bayern Munich, PSG, Arsenal, and Barcelona lead the way above a long list of other feeder clubs.</li> <li><strong>Most rosters are patchwork</strong>, where the median national team draws from 22 distinct club teams for the 26 players.<ul> <li>Two teams, Sweden and Cape Verde, have no shared club teams among the players: they each have exactly 26 club teams. The United States is not far behind with 24.</li> </ul> </li> <li><strong>High HHI nations</strong> like Saudia Arabia and Qatar have a closed-pool effect, where 90% of the players play in their own domestic league which causes the pool to draw from to be smaller.<ul> <li>The highest HHI European nation is Spain, followed by Germany.</li> </ul> </li> <li><strong>Domestic retention and concentration are correlated across all squads (r=0.83).</strong> Teams that keep more players at home do tend to be more club-concentrated because a domestic league is a far smaller pool of clubs to draw from. Spain is an outlier as its league has horizontal breadth -- six different La Liga clubs feed Spain's national team.</li> <li><strong>The chemistry hypothesis is inconclusive</strong>, but is not &quot;no effect.&quot; No trend across group stage → semifinals, but with N=4 in the two most advanced buckets and zero control for squad quality, this data can't distinguish &quot;no effect&quot; from &quot;too noisy to tell.&quot;</li> </ul> </div> <div class="section" id="club-concentration-metrics"> <h2>Club Concentration Metrics</h2> <p>In this table:</p> <ul class="simple"> <li>Top % = percentage of players from the top club</li> <li>Top-2 % = percentage of players from the top two clubs</li> <li>HHI = Herfindahl-Hirschman Index</li> <li>Effective clubs = <cite>1/HHI</cite></li> <li>Domestic % = percentage of players who play for a club team in their own nation</li> </ul> <table border="1" class="docutils"> <colgroup> <col width="20%" /> <col width="13%" /> <col width="28%" /> <col width="5%" /> <col width="6%" /> <col width="5%" /> <col width="14%" /> <col width="9%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Country</th> <th class="head">Distinct Clubs</th> <th class="head">Top Club</th> <th class="head">Top %</th> <th class="head">Top-2 %</th> <th class="head">HHI</th> <th class="head">Effective Clubs</th> <th class="head">Domestic %</th> </tr> </thead> <tbody valign="top"> <tr><td>South Africa</td> <td>12</td> <td>Mamelodi Sundowns</td> <td>30.8%</td> <td>61.5%</td> <td>0.2041</td> <td>4.9</td> <td>73.1%</td> </tr> <tr><td>Czech Republic</td> <td>11</td> <td>Slavia Prague</td> <td>38.5%</td> <td>50.0%</td> <td>0.1982</td> <td>5.04</td> <td>65.4%</td> </tr> <tr><td>Saudi Arabia</td> <td>9</td> <td>Al-Hilal</td> <td>26.9%</td> <td>50.0%</td> <td>0.1746</td> <td>5.73</td> <td>96.2%</td> </tr> <tr><td>Qatar</td> <td>8</td> <td>Al-Duhail</td> <td>23.1%</td> <td>42.3%</td> <td>0.1568</td> <td>6.38</td> <td>96.2%</td> </tr> <tr><td>Spain</td> <td>13</td> <td>Barcelona</td> <td>30.8%</td> <td>42.3%</td> <td>0.1479</td> <td>6.76</td> <td>65.4%</td> </tr> <tr><td>Egypt</td> <td>14</td> <td>Al Ahly</td> <td>30.8%</td> <td>42.3%</td> <td>0.142</td> <td>7.04</td> <td>65.4%</td> </tr> <tr><td>Turkey</td> <td>16</td> <td>Fenerbahçe</td> <td>23.1%</td> <td>46.2%</td> <td>0.1272</td> <td>7.86</td> <td>57.7%</td> </tr> <tr><td>Germany</td> <td>13</td> <td>Bayern Munich</td> <td>23.1%</td> <td>38.5%</td> <td>0.1243</td> <td>8.05</td> <td>73.1%</td> </tr> <tr><td>Jordan</td> <td>14</td> <td>Al-Hussein</td> <td>26.9%</td> <td>38.5%</td> <td>0.1213</td> <td>8.24</td> <td>46.2%</td> </tr> <tr><td>Iran</td> <td>14</td> <td>Tractor</td> <td>15.4%</td> <td>30.8%</td> <td>0.0976</td> <td>10.24</td> <td>65.4%</td> </tr> <tr><td>New Zealand</td> <td>19</td> <td>Auckland FC</td> <td>23.1%</td> <td>34.6%</td> <td>0.0917</td> <td>10.9</td> <td>0.0%</td> </tr> <tr><td>Argentina</td> <td>19</td> <td>Atlético Madrid</td> <td>23.1%</td> <td>30.8%</td> <td>0.0888</td> <td>11.27</td> <td>7.7%</td> </tr> <tr><td>England</td> <td>16</td> <td>Manchester City</td> <td>15.4%</td> <td>30.8%</td> <td>0.0888</td> <td>11.27</td> <td>80.8%</td> </tr> <tr><td>France</td> <td>18</td> <td>Paris Saint-Germain</td> <td>19.2%</td> <td>26.9%</td> <td>0.0799</td> <td>12.52</td> <td>30.8%</td> </tr> <tr><td>Portugal</td> <td>17</td> <td>Paris Saint-Germain</td> <td>15.4%</td> <td>26.9%</td> <td>0.0799</td> <td>12.52</td> <td>19.2%</td> </tr> <tr><td>Uzbekistan</td> <td>16</td> <td>Pakhtakor</td> <td>11.5%</td> <td>23.1%</td> <td>0.0769</td> <td>13.0</td> <td>61.5%</td> </tr> <tr><td>Mexico</td> <td>21</td> <td>Guadalajara</td> <td>19.2%</td> <td>26.9%</td> <td>0.071</td> <td>14.08</td> <td>46.2%</td> </tr> <tr><td>Belgium</td> <td>18</td> <td>Club Brugge</td> <td>11.5%</td> <td>23.1%</td> <td>0.068</td> <td>14.7</td> <td>11.5%</td> </tr> <tr><td>Netherlands</td> <td>19</td> <td>Brighton &amp; Hove Albion</td> <td>11.5%</td> <td>23.1%</td> <td>0.068</td> <td>14.7</td> <td>7.7%</td> </tr> <tr><td>Brazil</td> <td>20</td> <td>Flamengo</td> <td>15.4%</td> <td>23.1%</td> <td>0.0651</td> <td>15.36</td> <td>26.9%</td> </tr> <tr><td>Iraq</td> <td>20</td> <td>Al-Talaba</td> <td>11.5%</td> <td>23.1%</td> <td>0.0621</td> <td>16.1</td> <td>38.5%</td> </tr> <tr><td>Australia</td> <td>22</td> <td>Melbourne City</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>19.2%</td> </tr> <tr><td>Canada</td> <td>22</td> <td>Los Angeles FC</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>7.7%</td> </tr> <tr><td>Norway</td> <td>22</td> <td>Bodø/Glimt</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>15.4%</td> </tr> <tr><td>Paraguay</td> <td>22</td> <td>Palmeiras</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>11.5%</td> </tr> <tr><td>South Korea</td> <td>22</td> <td>Jeonbuk Hyundai Motors</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>26.9%</td> </tr> <tr><td>Uruguay</td> <td>22</td> <td>Flamengo</td> <td>11.5%</td> <td>19.2%</td> <td>0.0533</td> <td>18.78</td> <td>0.0%</td> </tr> <tr><td>Austria</td> <td>22</td> <td>RB Leipzig</td> <td>7.7%</td> <td>15.4%</td> <td>0.0503</td> <td>19.88</td> <td>11.5%</td> </tr> <tr><td>Curaçao</td> <td>22</td> <td>Miami FC</td> <td>7.7%</td> <td>15.4%</td> <td>0.0503</td> <td>19.88</td> <td>0.0%</td> </tr> <tr><td>Ecuador</td> <td>23</td> <td>Atlético Mineiro</td> <td>11.5%</td> <td>19.2%</td> <td>0.0503</td> <td>19.88</td> <td>7.7%</td> </tr> <tr><td>Ghana</td> <td>23</td> <td>Auxerre</td> <td>11.5%</td> <td>19.2%</td> <td>0.0503</td> <td>19.88</td> <td>3.8%</td> </tr> <tr><td>Scotland</td> <td>22</td> <td>Celtic</td> <td>7.7%</td> <td>15.4%</td> <td>0.0503</td> <td>19.88</td> <td>30.8%</td> </tr> <tr><td>Senegal</td> <td>22</td> <td>Nice</td> <td>7.7%</td> <td>15.4%</td> <td>0.0503</td> <td>19.88</td> <td>0.0%</td> </tr> <tr><td>Japan</td> <td>23</td> <td>Sint-Truiden</td> <td>7.7%</td> <td>15.4%</td> <td>0.0473</td> <td>21.12</td> <td>11.5%</td> </tr> <tr><td>Panama</td> <td>23</td> <td>Saprissa</td> <td>7.7%</td> <td>15.4%</td> <td>0.0473</td> <td>21.12</td> <td>7.7%</td> </tr> <tr><td>Algeria</td> <td>24</td> <td>Lille</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>11.5%</td> </tr> <tr><td>Bosnia and Herzegovina</td> <td>24</td> <td>Schalke 04</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>3.8%</td> </tr> <tr><td>Colombia</td> <td>24</td> <td>Crystal Palace</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>3.8%</td> </tr> <tr><td>Croatia</td> <td>24</td> <td>Manchester City</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>7.7%</td> </tr> <tr><td>DR Congo</td> <td>24</td> <td>AEL</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>0.0%</td> </tr> <tr><td>Morocco</td> <td>24</td> <td>PSV Eindhoven</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>7.7%</td> </tr> <tr><td>Switzerland</td> <td>24</td> <td>Sevilla</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>7.7%</td> </tr> <tr><td>Tunisia</td> <td>24</td> <td>Club Africain</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>23.1%</td> </tr> <tr><td>United States</td> <td>24</td> <td>PSV Eindhoven</td> <td>7.7%</td> <td>15.4%</td> <td>0.0444</td> <td>22.53</td> <td>15.4%</td> </tr> <tr><td>Haiti</td> <td>25</td> <td>Colorado Springs Switchbacks FC</td> <td>7.7%</td> <td>11.5%</td> <td>0.0414</td> <td>24.14</td> <td>3.8%</td> </tr> <tr><td>Ivory Coast</td> <td>25</td> <td>Charleroi</td> <td>7.7%</td> <td>11.5%</td> <td>0.0414</td> <td>24.14</td> <td>0.0%</td> </tr> <tr><td>Cape Verde</td> <td>26</td> <td>Chaves</td> <td>3.8%</td> <td>7.7%</td> <td>0.0385</td> <td>26.0</td> <td>0.0%</td> </tr> <tr><td>Sweden</td> <td>26</td> <td>Derby County</td> <td>3.8%</td> <td>7.7%</td> <td>0.0385</td> <td>26.0</td> <td>11.5%</td> </tr> </tbody> </table> </div> <div class="section" id="tournament-results-metrics"> <h2>Tournament Results Metrics</h2> <p><em>As of 7/12/26 ~ Semi-finals stage</em></p> <table border="1" class="docutils"> <colgroup> <col width="45%" /> <col width="18%" /> <col width="36%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Stage</th> <th class="head">N</th> <th class="head">Mean HHI</th> </tr> </thead> <tbody valign="top"> <tr><td>Group Stage</td> <td>16</td> <td>0.090</td> </tr> <tr><td>Round of 32</td> <td>16</td> <td>0.062</td> </tr> <tr><td>Round of 16</td> <td>8</td> <td>0.069</td> </tr> <tr><td>Quarterfinal</td> <td>4</td> <td>0.053</td> </tr> <tr><td>Semifinalist</td> <td>4</td> <td>0.101</td> </tr> </tbody> </table> <p>Squad concentration shows no clean relationship with how far a team advanced — the four semifinalists were actually the most club-concentrated group on average, but with just four teams in that bucket and no control for underlying squad quality, that's not evidence of anything either way.</p> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/chart.umd.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/chartjs-chart-matrix@1.1"></script></div> <div class="section" id="club-concentration-by-national-team"> <h2>Club Concentration by National Team</h2> <p>Boxes represent distinct club teams and the darker ones contribute more players than lighter ones.</p> <figure class="chart-card"> <div style="overflow-x: auto;"> <div style="position: relative; height: 980px; min-width: 680px;"> <canvas id="concentration-heatmap-chart"></canvas> </div> </div> <figcaption style="text-align: center; font-size: 12.5px; color: #666; margin-top: 6px;">Club rank within squad (1st = most-represented club)</figcaption> <div style="display: flex; align-items: center; justify-content: center; gap: 10px; margin-top: 12px;"> <span id="concentration-heatmap-legend-min"></span> <div style="width: 220px; height: 10px; border-radius: 5px; background: linear-gradient(to right, #cde2fb, #6da7ec, #2a78d6, #184f95, #0d366b);"></div> <span id="concentration-heatmap-legend-max"></span> </div> </figure> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/concentration-heatmap-data.js"></script> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/concentration-heatmap-chart.js"></script></div> <div class="section" id="top-feeder-leagues"> <h2>Top Feeder Leagues</h2> <figure class="chart-card"> <div style="position: relative; height: 620px;"> <canvas id="feeder-leagues-chart"></canvas> </div> <figcaption style="text-align: center; font-size: 12.5px; color: #666; margin-top: 6px;">Total players at the 2026 World Cup, by domestic league</figcaption> </figure> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/feeder-leagues-data.js"></script> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/feeder-leagues-chart.js"></script></div> <div class="section" id="club-count-distribution"> <h2>Club Count Distribution</h2> <figure class="chart-card"> <div style="position: relative; height: 460px;"> <canvas id="club-count-distribution-chart"></canvas> </div> <figcaption style="text-align: center; font-size: 12.5px; color: #666; margin-top: 6px;"> Distinct clubs represented in the 26-man squad </figcaption> </figure> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/club-count-distribution-data.js"></script> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/club-count-distribution-chart.js"></script></div> <div class="section" id="top-feeder-clubs-by-player-count"> <h2>Top Feeder Clubs by Player Count</h2> <figure class="chart-card" style="margin: 0;"> <div style="position: relative; height: 620px;"> <canvas id="feeder-clubs-by-players-chart"></canvas> </div> <figcaption style="text-align: center; font-size: 12.5px; color: #666; margin-top: 6px;"> Total players at the 2026 World Cup </figcaption> </figure> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/feeder-clubs-by-players-data.js"></script> <script src="https://robsiegwart.nyc3.digitaloceanspaces.com/data/world-cup-2026/feeder-clubs-by-players-chart.js"></script></div>