Anyone who has been hit by a jack whizzing across the terrain after being struck by a shot boule knows how much it can hurt and there is anecdotal evidence that injuries to players are more severe and more painful from these plastic jacks than from the wooden ones.
The FPUSA ban follows the lead of a couple of European federations that banned the jacks after noticing player reactions from being hit by the heavier plastic jacks. There is some suspicion that the plastic compresses upon impact from the steel boule and then is projected into the air with even more force than the wooden jack.
