Relevant, SpankBang is using machine learning (a system named BangBrain) to classify positions at scenes allowing you to skip to them. The training was done by

Relevant, SpankBang is using machine learning (a system named BangBrain) to classify positions at scenes allowing you to skip to them. The training was done by a CAPTCHA which showed various snapshots, on first visit, asking the user to select what sexual position it was depicting. CAPTCHA isn't shown anymore but screenshots can be found around.