We have taken turns looking at this under magnification. We have had it at shows including the National. Everyone we have shown it to is stumped. The only theory is that under 30x magnification on the back on the left side there is odd wear/damage on the extreme edge. Almost like scratches or wrinkling. Even under magnification it is very faint, but it's the best guess we can give for a card we were expecting to receive a 6-7 on.