Cup rotation: what our research can miss
Our chance is fixed when a Desk card is published, days before a cup tie's line-ups. Why rotation is the risk we cannot price, using this week's three cards.
On this page
Our chance on a Desk card is fixed when the card is published, and for a cup tie that is days before anyone knows the line-ups. Rotation is the one thing our research cannot see in advance, and cup weeks are when managers rotate most. So on every early-round cup card, the number describes the squad as the research found it, not the eleven who will start. We would rather say that plainly than let a confident percentage hide it.
This week's cup cards
| Tie | Card published | Kick-off (UTC) | Our pick | Our chance | Best price seen |
|---|---|---|---|---|---|
| Sunderland v Brentford | 22 Oct, 19:30 | 28 Oct, 19:45 | Sunderland | 37.1% | 3.9, Betfair |
| Liverpool v Chelsea | 25 Oct, 03:54 | 28 Oct, 20:00 | Liverpool | 50.3% | 2.65, PointsBet (AU) |
The Sunderland card is six days old by kick-off. Both quotes were taken at about 03:47 UTC on 25 October. Numbers from the BAI8 Desk preview.
Why rotation slips through
Each card comes from a full research run, every source graded, then the model, as set out in how BAI8 prices a fixture. The run reads injuries, suspensions, form and schedule. It can see that a club has a crowded week. What it cannot see is the manager's choice on the day, and in a cup tie that choice can change half the team.
Sunderland are the clearest example this week. They are playing in Europe as well as the league, and the Sunderland Echo expects Régis Le Bris to rotate heavily, with fringe players getting minutes. Our Sunderland number was set before any of that was known.
Why we do not adjust by hand
We could shade the number down on a hunch about rotation. We do not, because a chance that drifts with guesses is a chance nobody can check later. Our chance stays fixed and the price beside it is re-quoted, as explained in why our chance stays put when the price moves. When news lands that matters, we write it up separately and say which way it points.
What this does not tell you
It does not tell you which way rotation will cut. Both sides may rotate, and a weakened favourite against a weakened underdog may change nothing. It does not say this week's cup cards are wrong; it says they are older than the team news, which is true of every early cup card we publish. Check the line-ups before you rely on any of them.
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Common questions
Does BAI8 know the line-ups when it publishes a card?
No. Our cards for this week's Carabao Cup ties were published between 22 and 25 October, and line-ups come out about an hour before kick-off on 28 October. The chance is fixed at publication.
Why is rotation a bigger risk in cup games?
Managers change more players in early cup rounds than in the league, especially when their club is also playing in Europe. A side with five or six changes is a different team from the one the research studied.
What should I do with a cup card before the line-ups?
Read the publication date and the quote time, then check the line-ups yourself. If the side you are backing is heavily rotated, the card's chance is describing a stronger team than the one on the pitch.