The head of the sacrificial victim (presumably, the losing player) is held in one hand of someone presumed to be a winning player. Blood spurts out from the head and the trunk, where it appears as serpents. The winner's other hand holds the sacrificial flint knife. His knees have protective pads.
Although the head or heart were selected for the sacrifice as valuable objects, some skulls may have been used for the interior of the rubber balls to make them lighter. The rubber was then wrapped around the skull.
[Source: www.ballgame.org/sub_section.asp?section=2&sub_section=3 "The Mesoamerican Ball Game]
