Yes, the cycle.

Women have dual mating strategies, and hidden periods of ovulation. They differ from other animals in the animal kingdom in that it is not obvious when they are at peak fertility. For a simple reference a women has a period usually once a month. During that time, she is menstruating, roughly 14 days later she is ovulating. When she is ovulating she is at peak fertility. It cycles.

Well rounded science tells us that when women are ovulating, they desire masculine traits, and want as dominant a man as they can get. When menstruating, they desire more emotional intimacy.

science for anyone needing to verify:

http://www.medicalnewstoday.com/articles/272697.php

http://en.wikipedia.org/wiki/Sexual_motivation_and_hormones

http://www.science20.com/news_articles/what_do_women_want_it_depends_evolution_their_menstrual_cycle_and_gray_literature-129758

http://pss.sagepub.com/content/15/3/203.abstract

You should track the cycles of the women in your life. You should understand that at different times of the month they have different emotional needs. During ovulation, they want, crave to be manhandled, consumed, and dominated. During menstruation, they may desire more emotional vulnerability.

There are apps for your phone, or websites that will track this stuff for you. code red, pms buddy, period.me, etc.

Put your plates in. When they are bleeding, mark the calendar. Let it keep track of it for you.

How to use this information?

If dating multiple women?
Avoid PMS'ers. 1 week prior to mentrusation, women can be emotional and bitchy. Just skip them all together.

If you have 5 or 6 girls in the system, go see who is ovulating. When a girl is 14 days past menstruation, she usually craves being pounded like a caveman. spend time with a woman who wants what you want to give.

Sometimes, you may want some emotional closeness, some actual intimacy but you do not want to push her away, timing is key. If that is what you need for whatever reason, check the calendar, find the one most receptive who would have an emotional need matching yours and choose accordingly.

If you are in a LTR, or marriage, be aware of her basic human female wiring in how you approach shit tests. Perhaps she needs understanding, or perhaps she just needs to be put in her place. This may help you understand basic context.

Lastly.

Regardless of plates or LTR, if a girl is ovulating, and wants to be spending time doing girls night out, understand that if she is not chasing you during this time frame, she is not dedicated to you. Cold hard fact.