I don't think its the popping method, though I could be mistaken. This guy is really and I mean REALLY into snakes. The way he described it to me was that he can run his thumb and index finger down the sides of the snakes body at around 18 months and somehow determine the sex with with something like 85% accuracy and no stress to the snake. Like I said it all sounded very strange to me when I heard it because I have always been told to find a reputable person for probing. When I asked him about it he became very annoyed that I would offend my snake in such a manner. Very odd little man I assure you but his all his snakes are beautiful and he is very helpful when it comes to husbandry. I didn't buy the second snake from him, it turned out to be live fed and he helped me to convert it to frozen/ thawed despite my buying it elsewhere.

Thanks for the welcomes! You all seem very helpful. I think I will learn a lot here.