Very important post here for the boys (if you can get past the Chris Rock quote and move onto the article). It explains the phenomenon where, for the most part, you had to work, slave, beg, plead, etc., to essentially trick a girl into going out with you. However, there was that occasional girl that made it almost seem like she WANTED to go out with you. She made it easy. She presented herself to you, gave you a clear opportunity to ask her out, and not only said "yes" but also showed up for the date.
The simple answer? She was physically attracted to you, and the other girls weren't.
When I realized this, that if a girl likes you, she'll let you know, and if they don't, you're merely wasting time (not to mention money on cover charges at clubs), my strategy changed from one of pursuit to one of indifference. I believe I was about 19 at the time, and good thing I realized this that early on. From that point on I spent a mere fraction of resources most college boys did and most men do today AND had the same, if not better, results. Boys, do the same.