Cohort progression — Uczniowski Klub Sportowy "Delfinek" w Kutnie
Median season-best times of each birth-year cohort, overlaid by age — shows how consecutive groups developed at the same stage of training.
Event: 50 freestyle25 freestyle100 freestyle50 backstroke100 medley50 breaststroke50 butterfly25 backstroke25 breaststroke100 breaststroke
50 m freestyle men · 25 m pool
X: swimmer age in season · Y: median season-best time
born 2008 born 2007