I've been wondering if there's a way for, say a dealer with casino regulations (RRSRC) to detect and control desired or valuable cards only by riffling in RRSRC for riffle stacking or false dealing? I am aware of the fascinating world of cold stacking, peeking and tampered (or as erdnase likes to say: doctored) playing cards and their advantages, but in a situation with a borrowed untampered deck, the only methods that I found were cold stacking and riffle culling, both of which are almost impossible to master and do fluently.