Leagues move platforms for good reasons — a better app, better tooling, a commissioner tired of arguing with the old one. The cost is almost always the same and almost always discovered afterwards: the new platform starts at zero.
What does not survive
- Every past season. New platforms import rosters and members, not history.
- All-time standings and head-to-head records, which existed only as a view over that history.
- Draft history, trades and waiver records.
- The championship record — often the thing the league cares about most.
What you can rescue, and when
The order matters. Do this before you close the old league, not after.
- While the old league is still accessible, record each season's final standings — full finishing order, not just the champion.
- Note the champion, runner-up and third for each year.
- If the platform shows them, save points for and against per team per season.
- Screenshot anything that would be painful to lose. Screenshots are not data, but they settle disputes.
- Only then create the new league.
A finishing order per season is the minimum worth having. With it, titles, podiums, last places and average finish all still work. Without it, those seasons are gone.
Keeping one history across two platforms
A league that played four years on one platform and three on another has one history and two data sources. The old seasons come in as entered results, the new ones from the platform's API, and both feed the same all-time totals.
Seasons entered by hand should be marked as such. They carry titles and finishes but no week-level scores, so they cannot appear in single-week records — and a record book that hid that distinction would be lying about what it knows.