Incumbency and re-election rate
How many sitting councillors stood again, and how many won.
How it's calculated
Incumbents standing ÷ seats up; incumbents re-elected ÷ incumbents standing. An incumbent held a seat in the same ward (or its direct predecessor) immediately before this election.
Worked example
Heworth May 2023: Claire Douglas and Bob Webb, both elected in 2019, stood again and were re-elected; Ben Burton was new.
Source: Heworth ward, City of York — by-election of 15 January 2026 and May 2023.
Caveats
- Depends on matching the same person across elections. These figures stay unpublished until known duplicate-person problems are resolved.
- Where Elections Centre handbook flags exist (2021–25) they are used as ground truth.
Where it's used
- Council Previews (coming soon)
Other definitions
Vote shareChange in shareSwing (two-party, Butler)MajoritySwing needed to gainUncontested seatCandidates per seat / per wardContestation rateWinner's shareEffective number of partiesWinner's bonus (seats vs votes)Women candidates and councillorsTurnout (three methods)Council control and No Overall Control (NOC)Majority at riskPsephology National Share EstimateBy-election vote trackerNotional resultIndex of changeSplit-ticket indicatorNational Equivalent Vote