No sex on a first date increases your chances to find the better partner.

For a woman to find the best man it is better to hold off on having sex too soon. That has been discovered by some Brittish researchers by applying mathematics.

A reliable man

The analysts used a mathematic model to prove that reliable men are prepared to wait for the 'moment suprême' longer. "Bad" men will give up after the first date if they do not get any out of it immediately.
Professor Robert Seymour developped the model: 'Spreading your date over a longer period gives a woman the chance to get to know the man and gather information about him. By putting off the sex initially, she can minimize the risk that she's being used by a wrong copy. Woman that wait longer before they give in and have sex with the man, want to be absolutely sure that the sex is going to be good and that both parties enjoy it equally.

Compromise
Professor Peter Sozou stipulates that this strategy also has its weakness.
"The problem is that a woman first needs to identify the what makes a man less suitable, this can take a long time.
We live with the preconceived opinion that men want to have sex as quickly as possible, while a good partner would want to wait for a longer time.
As a woman you would have to make a compromise.
Ending up in bed too soon is not advisable, but waiting for too long can result in a walk away of the man.