Changelog
What changed in the Transfers benchmark, newest first.
A published score is only auditable if the rules behind it are traceable, so nothing here is retroactive. A version page is written once and never edited; when something has to change, a new version supersedes it and the entry below names what it replaced.
Entries record changes to the benchmark — the cohort, the pins, the rules. Software changes that leave every published number identical are not benchmark changes and are not listed.
2026-09-03 — First published board
The Transfers leaderboard began rendering published weekly snapshots. Ten snapshots exist, covering the weeks ending 2026-08-17, 2026-08-24 and 2026-08-31 across the five destination leagues.
Weeks before today were scored on already-played matches. The first weekly cycles were run retroactively rather than waiting three weeks for them to arrive in real time. This changed no rule: a prediction is still scored only on appearances made after its own lock, and the participant scored in these weeks locked its answers before any of them were played, which is why its information-at-lock reads as blind. What was compressed is the calendar, not the evidence.
Cohort at first publication: 809 cases across five leagues, 436 scorable.
2026-09-02 — Case registry rebuilt after the window shut
2026-09-02-transfers-cases-v2 replaces 2026-09-02-transfers-cases-v1.
Rebuilt from the arrivals snapshot dated 2026-09-02, the first taken after the summer transfer window closed, so the cohort is the season's completed intake rather than a partial one.
Arrivals snapshots are used whole and never merged. The source withdraws rows as well as adding them — a transfer recorded in August can be absent in September — so combining two snapshots would produce a cohort that never existed at any moment.
Entity crosswalk 2026-09-entity-crosswalk-v2 replaces -v1 in the same rebuild, after
reconciling players who had entered the registry with no match-source identity. See
Data & coverage for what that reconciliation refuses to
guess at, and why.
2026-09-02 — Case registry identifiers carry their date
2026-09-02-transfers-cases-v1 replaces 2026-09-transfers-cases-v1.
A transfer cohort is defined by the day it was cut, because the transfer window is still open on most of the days it might be cut. A month was not precise enough to identify which intake a pin refers to, so the identifier carries the full date.
No case changed. This is a naming correction, recorded because a version identifier that silently changed meaning would be worse than one that visibly changed shape.
2026-08-31 — Version identifiers stopped naming suppliers
The entity crosswalk's version identifier was renamed to 2026-09-entity-crosswalk-v1. The previous
identifier named two commercial data providers.
The Arena's credibility rests on being independent of any one vendor, and a version pin appears in the public spec and in every published snapshot — it is not the place to advertise a supply chain. The methodology is described in full throughout this documentation; what is avoided is phrasing that reads as an endorsement or an exclusive dependency.
No data changed.
2026-08-29 — Transfers benchmark opened
Contract 2026-09-transfers-distributional-v0, five destination leagues, reference pools cut from
the 2024/25 and 2025/26 seasons.
Participants predict a distribution over percentile bands of a player's per-match output at his new club, locked before his first appearance and scored against what happens afterwards. Scoring is ranked probability score against the realised distribution, divided by what the league base rate scored on the same outcomes.
The full opening rules are in the version archive.