T-shirt war - Rhett & Link

Now i found this stop motion very clever, as they did it through changing there shirts and interacting with them, so it could also be classed as pixilation to some extent. one thing i did wonder was how they managed to get back to the same positions each time after changing there shirts but depending what they were using they may have had software to track key frame positions which would make sense. Although the idea its self is really simple, coming up with the sequences, along with timings looks very difficult and scary to me, although the final product is an entertaining war between the guys shirts.