Error 1961 Fleer Basketball cards

1961 error cards are exceedingly rare.  They generally come in two types:  Wrong backs and severe miscuts.  I have broken the wrong backs into two groups.  One group is where the wrong back comes from the same row of the uncut sheet as the front and the other when it does not.  The theory behind this breakdown being that the former group were misprinted in the same batch and the latter were not. Of course, no one knows for sure.

One Theory (that admittedly does not explain all of them) during the printing process, the plates to print the backs were possibly loaded upside down. This would lead to the misalignment. This theory is strongly supported by the fact all "error back" cards have the blue stripe on the bottom of the card's back (rather than on the top like non-error cards). 

However, there is more to this story as the corresponding card backs do not match up like they should.  For instance, if simply loaded upside down, then the Wilt Chamberlain #8 card would align with the Clyde Lovellette #29 back rather than the Rudy Larusso #26. Yet, both known Chamberlain #8 error backs have a Larusso #26 back. Both #8 and #26 are located on the same row and both are 3 cards from their respective edges of the sheet (see green highlighted cards on the uncut sheet to the left). Similarly the Russell (wrong back) and Kerr IA (wrong back) are in this same row and match up from their respective distances from the edges. 

On the other hand, as seen above, many wrong back cards were printed with the backs of cards from totally different rows as the uncut sheet (ie, not aligned with its mirror counterpart or even from the same row).

What the above clearly does mean is that there are likely over a 100 wrong back cards still in the wild.  At a minimum, the 2 Chamberlains #8 wrong backs suggest that 2 entire sheets were misprinted, meaning likely all 132 cards on those 2 sheets were printed wrong.  

If you find a 1961 Fleer error back, please email me photos at 61fleer@gmail.com.