How does this bias manifest itself?
I think the problem is that there was a faulty batch of tables supplied with one leg shorter than the others which led to a slope/bias on the table that meant that the chips all slid to one end of the table. The crafty East Europeans sussed this out early and always chose seats at he "lower" end.
The problem can be solved by placing the requisite number of beer mats under the shorter leg.
I hope that this helps.