Unfortunately, Bergner's book offers no clues about how to determine when a woman is about to ovulate. If you work for the National Security Agency and have access to the PRISM database with a complete record of a woman's browsing history, web searches, phone calls and credit card purchases, then determining her point of maximum fertility is a trivial intelligence exercise. Computer geek Edward Snowden had obviously mastered that technique to land his pole dancing girlfriend, Lindsay Mills. Those of us without a top secret clearance have to resort to more rudimentary intelligence gathering techniques. For some men, this may require them to stalk their prospective mate a little more frequently than they are normally comfortable with.