What's a scenario that's highly unlikely due to the butterfly effect, that you would still like to explore anyway?
The rationale of it, we could say, is alternate history that instead of having a point of divergence, follows "ceteris paribus" where one thing changes and all other things remain equal.
For example, Iceland is settled in Greco-Roman times by Pytheas. History proceeds almost the same for centuries, with this lost island of pagan Ancient Greeks discovered by Catholic Irish monks and later Vikings in an otherwise OTL Medieval Europe.
The rationale of it, we could say, is alternate history that instead of having a point of divergence, follows "ceteris paribus" where one thing changes and all other things remain equal.
For example, Iceland is settled in Greco-Roman times by Pytheas. History proceeds almost the same for centuries, with this lost island of pagan Ancient Greeks discovered by Catholic Irish monks and later Vikings in an otherwise OTL Medieval Europe.