Winter Window: The Five Moves That Will Move Our Model Most
Transfers do not just change squads, they change the priors our engine uses. These are the five moves with the biggest modelling impact.
Every January our model has to re-learn a handful of teams. A single signing rarely matters. A signing that changes how a side builds up matters a great deal.
1. A new first-choice goalkeeper
Goalkeeping is the highest-variance position on the pitch and the one where our shot-stopping adjustment is largest. A change here shifts a team's expected goals against more than any outfield signing.
2. A deep-lying playmaker
Progressive passing from deep is the single strongest driver of chance volume in our feature set.
3. Losing a first-choice centre-back
Defensive partnerships take weeks to settle. We apply a temporary penalty to any back line that has played fewer than four matches together.
4. A manager change
Not a transfer, but it belongs on this list. New-manager bounce is real but short — roughly four matches in our data.
5. Squad depth in a European season
Rotation load is under-priced by the market almost every year. Teams playing Thursday–Sunday drop measurable output by the second month of a group stage.
