Single deck is almost extinct in Las Vegas *LINK*
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The raggedy Western, the almost-as-bad El Cortez, a table or two at Vegas Club, and a couple of tables at Binion's. Only at Binion's can you get any reasonable amount of money down, but watch out for pref shuffling. Four Queens also has a single deck table, but uses a cut card and is very low roller -- no reasonable money can be bet. You want single deck? Go to Reno.