Okay so this has been bothering me for THEEEE longest time - everyone says that, with a buffy, the probability of dwarf passing down is 75%, but that is not how probability works! Unless I have misunderstood a game mechanic (very sorry if I did), it's 25% on each cub. That doesn't make it 75% because probability, in this case, cannot be added like that.

I did the math, and the probabilities of passing, according to my calculations, is as follows:

Exactly 1 cub: ~42%
Exactly 2 cubs: ~14%
At least 1 cub: ~58%
At least 2 cubs: ~16%
No passing: ~42%
3 cubs: ~2%

Below is the math written out if you're interested