I'm not saying France should always form, just that it should regular enough. For now, I've more often seen France not form (for various reasons, none were Burgundy following the 1/400 ahistoric option) than France form. I agree with ribbon for the 90% (barring any player meddling

) : such very important events/situations should be nearly certain, tough allowing for occasional ahistoricity.
binTravkin, I know where we misunderstand. My first post's last paragraph was a bit upside-down, shortened. I meant that I didn't disagree with said possibility that Burgundy assumed the crown, but the last phrase was much more general. I was no more in the specific chain of events, but refering to the multiple (majority, in fact) occurences in my games where I did not see France form from DAU or BUR.
Really, my post was simply about stating a statistical fact. Expanding on that, I'd say that if you have 400 such chains of events (of double action-b options) in the game, you can be sure (at 99.99999999...%) to get at least one of those weird results. It has to be clear. And the risk of grossly ahistorical results is much higher when you don't have such double-checks (in many events, even one ahistoric choice is enough to screw it, even when double-checks are ensured). With one-in-twenty chances of ahistoric decisions, if you have 400 such potential history-shaking events, you get an average of 20 ahistoric decisions.
Probabilities and statistics, often have to be clearly explained and illustrated : many times, I see people ready to engage on so-called low-risks investments because they deem 2%-3% is not much a danger ; but when such risk is monthly, and their investment runs on several months, risks increase, and I have come to the conclusion that such crude analysis are too often misleading.
And, to hint at another difficulty : when a specific event/situation needs to go through a sequence of several events, which each have a possibility for screwing up, risk dramatically increases. Say that Dauphiné needs to go through six two-choice events (itself or of other countries - I make up the number, I haven't analyzed the event chain) to become France, you only have 72.3% probability of having France, as the chain can be screwed in six occasions. This means that
three out of ten such event chains will blow up, simply because of statistics.