Cohort progression — Kaliski KS ,,Włókniarz'' 1925 Kalisz
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 backstroke200 freestyle50 breaststroke100 backstroke100 butterfly100 medley200 backstroke100 breaststroke200 medley25 unknown400 freestyle25 backstroke25 freestyle200 butterfly200 breaststroke
50 m freestyle men · 25 m pool
X: swimmer age in season · Y: median season-best time
born 2016 born 2014