Rui Chen, Shiyan Sheng, Xiaoyu Liu
Tournament-time foreign-club exposure was confirmed for 1/21 players (4.8%), whereas post-youth adult competitive access was officially verified for all 21 players. Under the primary strict senior-tournament rule, SCL-3/4 was confirmed for at least 6/21 players (28.6%); under a broader rule including played Copa América 2019 minutes, this increased to 9/21 (42.9%). Club-only PEEX-3/4 was confirmed for at least 10/21 players (47.6%) after official-source reconciliation. Raw intercoder agreement was high, but source reconciliation still corrected evidence-sensitive classifications, supporting the need to distinguish reliability from endpoint verification.
INTRODUCTION: Youth tournament success is visible, but it is not itself evidence of later adult access, elite club exposure or senior national-team contribution. Coaching departments therefore require source-traceable follow-up after selection. This methodological case study introduces a proof-of-concept Four-Gate Coaching Audit for converting a youth selection event into a longitudinal, player-level evidence register.
METHODS: The audit is a monitoring protocol rather than a validated prediction model. It separates four non-substitutable constructs: documented selection context, post-youth adult competitive access, club-only Post-Youth Elite Exposure (PEEX) and Senior Contribution Ladder (SCL) status. Codes are assigned only from official federation, competition, league or club records; unestablished evidence is coded as NE rather than zero. The demonstration uses the complete 21-player final participant cohort of Japan at the FIFA U-20 World Cup Korea Republic 2017.
RESULTS: Tournament-time foreign-club exposure was confirmed for 1/21 players (4.8%), whereas post-youth adult competitive access was officially verified for all 21 players. Under the primary strict senior-tournament rule, SCL-3/4 was confirmed for at least 6/21 players (28.6%); under a broader rule including played Copa América 2019 minutes, this increased to 9/21 (42.9%). Club-only PEEX-3/4 was confirmed for at least 10/21 players (47.6%) after official-source reconciliation. Raw intercoder agreement was high, but source reconciliation still corrected evidence-sensitive classifications, supporting the need to distinguish reliability from endpoint verification.
DISCUSSION: The study contributes a construct-separating audit protocol for monitoring youth-to-senior pathways without treating youth selection, overseas registration or senior-team association as automatic evidence of conversion. The findings are official-confirmed minimums and do not imply causal effects, player-quality rankings or national-system superiority.