This study was conducted to evaluate and compare declarative and procedural knowledge among the Iranian soccer schools’ players with different age and level of experience. Totally, 456 soccer schools’ players with U-10, U-13 and U-16 age groups and three categories of high, middle, and low experience of competition were included in this study and completed the Soccers’ Tactical Knowledge Test. Participants responded to a written multiple-choice test on theoretical information and rules and representative figures of a game situation for evaluation of declarative and procedural tactical knowledge, respectively. Results showed significant differences in total, declarative ,and procedural tactical knowledge among different age and level of experience groups. Results of the Bonferroni post-hoc test revealed significant differences only between U-16 and U-13 with U-10 groups, and between high and middle with low level of experience groups (p=0.00). In the sub-scales of the declarative and procedural tactical knowledge, U-16 and high-experienced players performed better than U-10 and low-experienced ones (p=0.00). Furthermore, significant differences observed between U-16 and U-10 players in declarative and procedural tactical knowledge (p=0.00) confirmmed that not only length of time to explore sport-specific concepts, but also psycho-physical development of children/adolescents influenced acquisition of tactical knowledge in invasion team sports like soccer possibly due to soccers’ competitive experience. Our findings suggested that improvement of declarative and procedural tactical knowledge in the initial years influences the individuals’ future success in soccer.
