Table 2. Cluster characteristics. Cluster SPR AVG END Playing Position 3 F | 1 B 3 F | 4 AM | 2 DM | 2 B | 3 CD 1 F | 2 AM | 2 DM | 1 B Competitive level 2 U21 | 2 U18 14 U18 5 U21 | 1 U18 Age (years) 17.71 ± 1.16 17.72 ± 0.69 18.20 ± 1.00 Height (cm) 174.5 ± 4.7 178.9 ± 4.9 176.3 ± 6.3 Body mass (kg) 70.5 ± 2.3 68.9 ± 7.4 69.4 ± 5.8 BMI (kg/m2) 23.2 ± 1.5 21.5 ± 1.8 22.3 ± 1.2 The playing position, competitive level, and the M ± SD for age, height, body mass, and BMI across the three identified clusters. Playing positions are abbreviated as F = Forward, AM = Attacking Midfielder, DM = Defensive Midfielder, B = Back, and CD = Central Defender.