Cohort progression — Športno društvo Delfin
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 freestyle100 freestyle50 butterfly50 backstroke50 breaststroke200 freestyle100 breaststroke100 butterfly400 freestyle100 medley100 backstroke200 breaststroke200 medley
50 m freestyle men · 25 m pool
X: swimmer age in season · Y: median season-best time
born 2011 born 2010