Because of the 15% rule, the percentages from primary elections

[MineralMan]

11. I've never voted in a state where you voted for delegates.

I don't know what states still do that. at this site: https://www.thegreenpapers.com/P20/D, if you click on links to the individual states, you can find a detailed description of how that state chooses delegates after the primary elections.

There are variations among the states, but the concept is always the same, and all use the 15% viability rule in one way or another.

Delegates are awarded proportionally, according to the vote counts, but nonviable candidates are not eligible. So, the proportions for viable candidates are normalized to a 100% total among them. That can cause rounding issues, which can alter delegate counts by one or two delegates in some cases.

It's fairly simple. If, after normalizing proportions to make up 100%, a candidate has a fractional percentage above .5%, that candidate gets the extra delegate and candidates under .5% in the calculations don't. So if you have two candidates and one has 49.6% and the other has 49.4%, the candidate with the .1% advantage is awarded 51 delegates and the other gets 49

When things like that happen, the losing candidate either cries in his beer or screams bloody murder. Neither action changes the result, however.