I guess the issue rarely came up. First, not many places would have that many roulette tables. Second, they more likely had symbols (fleur de lis, comet, diamond, etc.) or letters of the alphabet to designate the tables.
Robt.
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Victor Mature and Ona Munson in wonderful scene of the main roulette pit in "The Shanghai Gesture" (1941), the great Josef von Sternberg noir movie about degradation, revenge and addiction. It also stars Gene Tierney and Walter Huston. Must-see movie with a lot of gambling and sin. Munson is seen at the upper-right, at the entrance to the pit in white dress and arms outstretched. Mature is down aways and in front of her; he is wearing white Asian garb and a fez.
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