Hi Bob; Thanks for your response to my BB post. Don't know if you have any experience as a coin collector... but I know there are many coin collectors who also collect chips so perhaps they can relate to a similar situation with respect to early U.S. coinage before 1836.
Back then, silver coins had inscriptions around a plain smooth edge, where the edge reeding or grooves appear on today's modern coinage. In the case of a half dollar, the edge inscription read "50 cents or half a dollar". This edge lettering was applied to the silver blank planchets before the actual coins were die struck by hand screw presses (this was before the steam press was invented in 1836). After the edge lettering was applied to the blank silver planchets as they came off the edge lettering machine, the planchets fell into woven baskets and were carried to the coining presses. There the now silver lettered edge blank planchets were hand fed onto the coining press with no regard as to whether the edge lettering was right side up or upside down. The result was that after the coin was now struck with the heads/tails die designs, if one looked at the half dollar edge with the obverse (heads) side up, sometimes the edge lettering was right side up, sometimes it was upside down. The same thing happens on chips with multiple SxS edge inserts. If both sides of a chip are of the same design, (like most regular issue rack chips are) there is no "reversal" effect detected. But, If the obverse side illustration is different than the reverse side (like a coin; or like many of todays commemorative chips) then the edge inserts appear to be "backwards" or "reversed" on random samplings of a group of similar chips which have multiple SxS inserts.
This sometimes "reversal" of edge inserts on chips occurs on random samplings of ALL chips which have different front and back designs and which also have multiple color SxS edge inserts. I hope this illustration explains somewhat more clearly how this phenomenon happens. Archie