A thread in the EU IV forums got me wondering how the Catholic League managed to hold out so well during the 30 years war.
It seems to me that Spain, Austria, PLC and some German minors managed to hold off the rest of Europe.
So how the heck did they manage to do it?
First you had half-HRE+Spain+Poland against half-HRE+Ottomans, which ended with the Ottomans fought to a draw and half the HRE ground down. Meanwhile there was a French-English war with shades of French civil war.
Then you continued with Denmark and some-HRE (with some Anglo-French support; those guys...) vs half-HRE with Spanish support (the Spanish being again occupied in the Netherlands), which ended painfully for the Danes.
This phase ended more or less in complete catholic victory, so push the reset button here on all the HRE except Austria - they're now all dead or out, even if they still provided the battlefields.
Enter Sweden with French-Dutch support, fighting Austria with Spanish support. Sounds not so uneven, but again, in the end Sweden lost.
At the same time there was Sweden/Russia vs Poland going on, which at this time was still fairly even (given the Swedes were also occupied with Germany), followed by another brief Polish-Ottoman fight.
Sweden lost like Denmark before them, so the French finally got into it seriously, bringing about the final phase which firmly included the Netherlands and more westerly Europe, giving France/Netherlands/Sweden(/England) vs. Spain/Austria, but with the understanding that Sweden and Austria were half-dead it's mostly France/Netherlands vs Spain and Sweden/half-HRE against Austria/half-HRE. Here the Habsburgs lost, but then the Danes were re-entering
against Sweden, so the anti-Habsburg victory mostly ended up reversing the price of the early protestant losses in the Palatine, Danish and Swedish phases (still, it did manage to break Spain as a superpower).