Most off-center strikes and some uncentered broadstrikes show a collar scar on the face struck by the anvil die. The collar scar is produced when the part of the misfed planchet that protrudes outside the striking chamber is forced down upon the top of the collar and depresses it. The collar floats on springs in the older style Bliss press and we may presume that functionally similar arrangements exist in other press models.
Figure 2 shows an off-center 2000-P nickel with a strong collar scar on the obverse. The unstruck part of the planchet is also slightly cupped up toward the reverse, another indicator of inverted die installation. While not all off-center strikes show cupping, its presence is a reliable indicator as to which die functioned as the hammer die. Cupping in a simple off-center strike (both faces die-struck) is always toward the hammer die.