Table 1. Overview of the different groups analyzed
Group name Group Definition Sample Size (n)
German Population The German male population born between 1992-2000 (U12-U18) 3216811
Licensed Players All players affiliated to the German Tennis Federation (DTB) born between 1992 and 2000 (U12-U18). 120851
Ranked Players All players having a ranking position on the Under 18-Youth ranking list born between 1992-2000 (U12-U18) 7165
Regional Squad All players selected from the regional federation coaching staff as the most talented players born between 1992-2000 (U12-U18) 381
National Squad All players selected from the national federation coaching staff as the most talented players born between 1992-2000 (U12-U18) 57
Senior Players Top 50 senior players of the national ranking (including the Davis Cup team) 50