IANAL either but final adjudication is more important that what anyone claimed in the course in the trial.

If you claim X, but the court adjudicated that Not-X is true, then you can build off the fact that Not-X was adjudicated. It doesn’t matter if you claimed X at one point

I agree. I think in your scenario, if you try to claim X in case B, after case A decided non-X, that might get you in trouble.

My question was more about when X was not adjudicated in case A. Do you get to claim the opposite in a different case? Or are you bound by your claims?

There are too many hypotheticals to answer the question with any degree of accuracy.

You are certainly not bound to keep claiming X though. I mean, there's such a thing as new information and research. If 10 years ago you claimed X, and the latest science is different now, then I don't think a proper judge or arbitrator would hold that against you. They will weigh the evidence provided at the time of the argument for the claim.

Of course it's gonna look bad if there were no significant events or it happened a week ago.

But that's only going to be considered if the counter-party even brings it up as an argument. There's a host of reason they may not choose to argue on that platform, not to mention in many situations there's no way to find out. Certainly if it's taking place in private arbitration, different counter-parties aren't going to know the arguments you claimed in different cases.