Unduel supports list versioning which allows you to take ranking snapshots of your lists for a defined time period. This is perfect for gracefully supporting a couple different scenarios:
The latest list version will feature live, updating rankings. And users can browse historical rankings from previous versions using a drop down on the list page.
Rankings for a past version are calculated, then frozen, the moment it stops being the latest version. Past version rankings will not change and cannot be voted on. Rankings for a past version are calculated only based on votes that were made during its defined period.
To manage a list’s versions, go to one of your list pages, and click “Edit List”. This will take you to the Make a List page for this list. Enable “Advanced Controls”, then click “Manage List Versions” in the List Versions section. Click “Add New Version” to get started creating your first version.
Version Name - A name for the version e.g. “v1.2”, “May 2025”, “Season 5”. This is a user facing name, so pick something that will be most clear and recognizable to users. Version name can be changed after creating the version.
Start Date - The real world date when this version starts. It could be a release date of a game patch, or the 1st of the month that you are collecting votes for. Make sure it reflects the actual date of whatever you are making this version for. Start date must be in the past, and it cannot be before the start date of any other versions you have on a list. So you’ll need to create versions in chronological order. For your first version, you should still pick a start date that makes sense, such as the initial release date of a game. But if you weren’t collecting votes at that time, you can skip all the way to the first version where you started collecting votes.
Don’t worry if you haven’t added any list versions yet and multiple real world versions have already gone past. You can still go back and add all past versions in order. Accurate past version ranking snapshots will still be generated. Going forward, best practice would be to add the new version as soon as it comes around in the real world.
There is no end date field, because the start date of the next version implies the end date of the version before it.
Start date cannot be changed after creating the version. The version will need to be deleted and recreated to change the date. Versions must be deleted in reverse-chronological order as only the latest version can be deleted. Because of that, it’s best to get the start date correct the first time. If you do have to delete multiple versions to fix a previous start date, you can still recreate all versions and version rankings by readding them. However, if previous voters updated their rankings or if you deleted rankings for an item, the newly generated version snapshots can be partially incomplete.
Vote Count K Value - An optional value that lets you manage stat blending between list versions. Instead of rankings starting from scratch when a new version is created, you can fall back on the data from the previous version.
Once an item reaches K votes on the latest version, then only votes during the latest version’s period will be used for calculating its ranking. But if an item has a vote count less than K on the latest version, then the previous version’s rankings will have an influence proportional to: