The shift to shorter events
Change in how much each event is raced per swimmer (2010→2025). The toughest events (400 IM, 200 fly, 800 free) have declined; sprints and the 400 free have grown.
Distance racing by age
Share of starts that are ≥200 m. It peaks in the mid-teens, and the youngest now race more distance than in 2010.
Specialization rises with age
The young are all-rounders; with age more swimmers concentrate on one stroke (specialist share) and butterfly's share grows. (2025)
What marks the elite?
How often the elite (best WA ≥ 600) vs. everyone else specialize in each discipline. Sprint-fly and distance-free mark the elite; back/breast are level-neutral; sprint-free is more the developing default. (2025)
Event popularity & session load
Average entries an event draws at a meet that offers it (long course, 2025). Sprints and 100 s fill the sessions; the long events now draw only a handful — 1500 m ~8, 200 fly and 800 m ~14, 400 IM ~16 per meet. Directly useful for building the timeline and deciding whether an event is still worth offering.
Where they compete
Which championship each age belongs to — and what share of that age group's active swimmers actually competes there. Rollo reaches nearly half of the youngest; IKM and SM are more selective. (2025)
% = share of the age group's active swimmers who competed at that championship (2025). 13-year-olds compete in both Rollo and IKM; SM/NSM is also open to 12–14s and adults.
Rollo's open 50 m freestyle: 470 swimmers (41 %) race it, and 353 (31 %) come only for it — no qualifying time needed.
Championship participation by single age
Each single age's active swimmers, split by which championship they raced (2025). Overlaps get their own colour: at 13 many swim both Rollo and IKM, and at 14–16 a growing number swim both IKM and SM. Light green = Rollo swimmers who came only for the open 50 m freestyle (no qualifying time). Grey = no championship. Toggle count vs share.
Competitive tiers
What a normal competitive swimmer looks like at each championship tier (by cut times) — medians pooled over 2022–2025. Parentheses show the interquartile range (p25–p75). Harrastajat = competes but below cuts; Masters = 19+ below SM level.
| Tier | Swimmers | Age | Comps/yr | Events/yr | Starts/yr | Improve/yr |
|---|---|---|---|---|---|---|
| pre-Rollo | 1,862 | 9 | 3 (2–6) | 3 (2–5) | 5 (2–12) | 63.7% |
| Rollo | 5,315 | 12 | 11 (8–13) | 10 (8–12) | 34 (24–44) | 40.7% |
| IKM | 3,197 | 14 | 11 (9–14) | 12 (10–14) | 37 (27–48) | 15.7% |
| NSM | 792 | 17 | 11 (8–15) | 11 (8–13) | 34 (24–47) | 4.6% |
| SM | 3,005 | 18 | 12 (7–15) | 10 (6–13) | 39 (20–57) | 2.2% |
| Masters | 3,003 | 42 | 2 (1–4) | 4 (2–6) | 6 (3–11) | -0.7% |
| Harrastajat | 5,548 | 12 | 3 (2–5) | 4 (2–6) | 6 (3–12) | 14.2% |
Tier mix over time
How many swimmers sit at each tier each year.
The teenage drop-off
Number of competing swimmers by age (2025, all courses). It peaks at 12 and halves by 16. Girls are the clear majority when young but drop out faster — boys outnumber them by the late teens. 64% of 13-year-olds were still racing two years later.
When careers end
Of swimmers whose last season was 2023 or earlier (11,479 swimmers, so a return would already show), retirements cluster at the end of the long-course / spring season (May–July). The short-course season end (Nov–Dec) doesn't stand out, and almost nobody stops in September — those who continue return when the autumn season starts.
Spring / long-course end (May–Jul): 35.6% of retirements, though only 20.3% of all meets fall then. Short-course end (Nov–Dec) is 17.4% — the same as its share of meets (18.6%).
Do they wind down first?
No. Competition and start volume stays near normal right through the last full season (swimmers with ≥ 5 seasons). The final calendar year only looks lighter because they stop partway through it — they don't cut back before quitting.
Development benchmarks — where a swimmer sits
Each swimmer's season-best WA points by age: median (middle of the field) and top decile (long course). A coach can place a swimmer against the national field. (2025)
Improvement decelerates: a two-year gain is about 1.6× the one-year gain — not double. The young improve fastest, and the pace eases with age.
Birth-year cohort strength
Each birth year's size measured at the same age (12) so cohorts are comparable. A thin year now = fewer championship swimmers a few years out. The full pipeline view is in the cohort tool.
Is the sport growing?
Distinct competing swimmers per year (all courses). The number is stable and slightly up (5298 → 5924 over 2010–2025). Meets rose 360 → 397 and starts 108,000 → 138,000.
Based on all long-course (50 m) results with WA points, swimmers with ≥ 6 starts. Age = year − birth year. Updates as new data loads.