If talking a single generation, this would be the number to use. That is, the 55 segment scrambling that your parents got will be passed on to you.

I was talking with someone about having different ancestry from one's siblings. I was unsure of how frequently chromosomal gene swapping occurs. This answers the important question, which is units of inheritance. That is, instead of calculating inheritance as 23 units, slightly less than 100 appears more accurate. This makes percentage DNA almost precisely the expected value, but the standard deviation should be such that rare cases of one sibling being e.g. Jewish while the other sibling lacking that ancestry may occur.