When my great-grandma died, she had been predeceased by one child and one grandchild, while leaving others in each of those generations living. (Three children, call them 1, 2 and 3. 1 had children 1A, 1B, 1C and 1D. 1D was the predeceased one, who left 1Di and 1Dii.)
Per stipes was therefore the only way to distribute with impacting the original "one third to each child" principle.
2 and 3 each got 1/3. 1A, 1B and 1C each got 1/12. 1Di and 1Dii each got 1/24.
Me? I'm 1Bi. I got nothing, but I have my mom, which neither she, her siblings nor niece/nephew can say.