A "Greater Saxony"
Either John George of Saxony accepts the Bohemian throne in 1617, or he dies childless in the early 1610s (as did both his brothers OTL), and Saxony reverts to the Ernestine line under Johann Philip of Saxe-Altenburg, and *he* accepts it.
You now have a Bohemian crown that includes the Electorate of Saxony - a state perhaps strong enough to compete with Brandenburg-Prussia. This changes the events of the Thirty Years War (if that isn't butterflied) since the Elector Palatine is not involved, so there's no excuse to confiscate his Electorate, while OTOH (since a Prince can have only one Electoral vote) either Saxony's or Bohemia's is available for reallocation and can be given to Bavaria w/o the need to confiscate anything.
Could get interesting.
Either John George of Saxony accepts the Bohemian throne in 1617, or he dies childless in the early 1610s (as did both his brothers OTL), and Saxony reverts to the Ernestine line under Johann Philip of Saxe-Altenburg, and *he* accepts it.
You now have a Bohemian crown that includes the Electorate of Saxony - a state perhaps strong enough to compete with Brandenburg-Prussia. This changes the events of the Thirty Years War (if that isn't butterflied) since the Elector Palatine is not involved, so there's no excuse to confiscate his Electorate, while OTOH (since a Prince can have only one Electoral vote) either Saxony's or Bohemia's is available for reallocation and can be given to Bavaria w/o the need to confiscate anything.
Could get interesting.