We received our mail-in ballots. I asked whether we should vote for all 6 delegate candidates. It is confusing for many of us. For example, under Biden’s name, there are 6 candidate delegates listed, see above.
I had received different opinions and someone suggested that voting for all 6 delegate choices defeats your purpose?
Since I personally know one of the delegates I asked them and got the following response:
Biden’s allocation of delegates will be based on the percentage of the total votes that HE gets. This is quite separate from the number of votes each delegate receives. The number of votes each delegate receives will determine who is elected delegate, in descending order, alternating by gender. ie, if 10,000 total votes are cast for POTUS and Biden gets 5,000 votes, he will get 1/2 of the number of delegates in the 1st congressional district (CD NY-01). If you “bullet vote” the delegates (vote for only 2 or 3 out of 6) you increase the chances of those specific delegates of being elected.
R&R - Reachout and Rebuild 
There is also a 15% threshold, which means that only candidates who receive a minimum of 15% of the votes can receive delegates. IMHO, I think The Green Papers internet site has a good description of the rules and processes for the 2020 Democratic Presidential Primary. https://www.thegreenpapers.com/P20/NY-D
Thanks, Diane