Cohort progression — KS "Swimmers Centrum Ślęza"
Median season-best times of each birth-year cohort, overlaid by age — shows how consecutive groups developed at the same stage of training.
Event: 100 freestyle50 freestyle50 butterfly100 breaststroke50 backstroke200 medley50 breaststroke100 backstroke100 butterfly200 freestyle200 breaststroke400 freestyle
100 m freestyle men · 25 m pool
X: swimmer age in season · Y: median season-best time
born 2009 born 2008