Agree the unissued cards created chase cards but think it was unintentional and due to contract issues. Cards 10,44,61,72 and 81 in series 1were skipped. In Series 2 the skipped cards were 94,107,131and 156. According to Dean Hanley the skipping was to fill holes on subsequent sheets due to failure to secure contracts for players (unknown) that were originally planned to be in the series. That skipping worked until they got to the last series when they ran out of players under contract resulting in the 6 unissued cards in the last series.
Here is George Vrechek's take on the 53 printing
https://r.search.yahoo.com/_ylt=AwrJ...ebLZyxhR7kh1U-