The two most obvious factors in such a decision are how much they liked who they met and how likely they think they will get a "yes" from them.
There is no point in asking a person for a second date no matter how much you like him or her when you feel there's no chance of getting a yes.
What percentage of initial dates resulted in matches?
https://colinleverger.github.io/speed-dating-experiment-r Here is the knitted R script that I used to do the data exploration.
We study dating behavior using data from a Speed Dating experiment where we generate random matching of subjects and create random variation in the number of potential partners.
In order to make a match, you need to request another date and get that request accepted.
This means some people who got very high match rate must have requested a second date with almost everyone they met and they got their favor returned.