Cohort progression — UKS "VIGOR" przy SP im. Jana Pawła II w Łętowni
Median season-best times of each birth-year cohort, overlaid by age — shows how consecutive groups developed at the same stage of training.
50 m breaststroke men · 25 m pool
X: swimmer age in season · Y: median season-best time
born 2011 born 2010