Win/win also has some teeth under it somewhere, or they’d just give you everything yes? In your scenario, why not give you a billion dollars vs a million vs 100k?
BATNA (and I am every familiar with the term, as I’ve had to do a significant amount of negotiation) is the ‘plan B’ if there is no acceptable ‘good’ agreement.
If someone has no acceptable BATNA, their negotiation is essentially ‘please don’t beat me up too bad’, not ‘let’s see if we can agree on something that works for both of us’. No BATNA means you aren’t effectively negotiating, just begging to not be abused too badly.
Sometimes an employer doesn’t have a BATNA option, but that is rare. Usually it’s the employee which doesn’t have a plan B.
A BATNA when doing negotiations over salary, for instance, might be taking another offer with an otherwise less desirable company. Or continuing a job search for more time. Or becoming a sugar baby for an older woman somewhere, etc. or filing for bankruptcy.
Knowing what your own (and what the other sides) plan B is, is important to actually have a successful negotiation, because when your offer starts to look less desirable than their plan B, it isn’t going to go well.
