How Swoop works

Every call you make is timestamped and kept forever, exactly as you made it. Change your mind as often as you like: each change is a new entry, and it only counts from the moment you make it. Nothing earlier is rewritten.

We score you against the Index as it stood at that moment, using every report from the time it was published (not when we got round to reading it). So calling it after the news is out earns almost nothing, even if our page hadn’t caught up yet.

Accuracy is measured with the Brier score, a standard rule for scoring probabilities: the squared gap between what you said and what happened. Say 95% and be wrong, and the penalty is huge; say 60% and be wrong, and it’s modest. The only way to score well over time is to say what you actually believe.

Every transfer has several possible endings (each club, another club, or staying), and your call must add up to 100%. You can’t back two clubs at 90% each.

For every moment you hold a call, we compare your error with the Index’s error at that same moment, and average it over the time you held it. That average is your edge. Then it’s weighted by how long you held your view before the result locked: a week or more gets full weight, a day about 40%, two hours about 10%.

Points = 100 × edge × min(1, √(time held ÷ 7 days))

So time counts in two honest ways. Late in a window the Index already knows a lot (a move with no progress fades towards “stays” as the deadline nears), so agreeing with it then earns almost nothing. And a bold late call (backing a move the Index puts at 3% with hours to go) earns real Points if it comes off and costs about as much if it doesn’t, so spraying long shots on deadline day loses. How long a saga runs doesn’t matter: calling months before a window opens is neither penalised nor padded.

Doubting a hyped move that then collapses scores exactly as well as backing a long shot that comes off. Scepticism is a skill too.

• Calls close at the deadline. Where the leagues involved close on different days, calls close at the earliest, and a move can still be registered until the latest. Each saga shows a live countdown.
• Only an official source settles a move: the club’s own website or official account, or the league’s registration list. Journalists never settle anything, however reliable; they only move the Index, which stays below 98% until it’s official.
• Official news closes calls at once. When a club announces a deal, the saga shows Closed: pending verification, locked at the moment the news was first public. Nobody can call a result that’s already known.
• A move counts if the player is registered with the new club under that league’s deadline. A deal lodged before the deadline and announced up to 72 hours after still counts, locked at the deadline.
• Wrong window: a move in a later window means he stayed, for this one. Loans count as moves. A pre-agreed transfer counts in the window it takes effect.
• Can’t be verified? If the outcome still can’t be confirmed 14 days after the deadline, the saga is voided: no scores for anyone, and everyone who called it is told.
• Results are provisional for 7 days, and become final only once the evidence has been re-checked and confirmed. Then they’re frozen.

For every transfer we record the information breakthrough: the first moment it became widely foreseeable. That’s an official club statement, a second independent credible report of an agreement, or the Index reaching 85% on the evidence. One journalist on their own is never enough, and outlets repeating that journalist don’t count as confirmation.

Saw it coming: 60%+ on the club he joined, 30+ points above the Index at the time, at least 3 days before the breakthrough, and you held your nerve (50%+) until it.

Saw through it: the Index had a move at 60%+, you said 25% or less, at least 3 days before it fell apart, you stuck with it, and it didn’t happen.

Both are verified only once the result is final (7 days after confirmation), and both are judged against the higher of the Index we showed and the Index on the published evidence, so nobody gains from our being slow. Every bold call stays on your record, right or wrong, so luck can’t hide.

Swoop Rating is pulled towards 50 until you’ve got plenty of settled calls, and it shows a range (e.g. 62 ±8). Below 10 settled calls, or while the range is wide, it’s marked provisional and you’re not on the all-time table yet. Making lots of calls that just copy the Index keeps you at 50: volume isn’t skill.

• Show anyone your open calls before the transfer settles. Fan figures only appear once 5+ people have called it.
• Change a final result. Once a result is final its scores are frozen; every score we’ve ever written is kept.
• Let you switch clubs mid-window to help a fanbase: you represent the club you had when you first called that window.
• Change the rules quietly. Each transfer settles under the scoring version it resolved with, and earlier results keep theirs. Before November 2026, Points were weighted by the share of the saga you held a view for; from November 2026 they’re weighted by how long you held it.

Full methodology, formulas and worked examples are published with the code. See the tables.