[aidenn0]

I haven't been in the contract-bridge scene in a long time, but had a friend who was competitive at the regional-level, and the impression I got was that partner-signalling was hard to get away with just because opponents would recognize abnormal results so quickly; at that level you would regularly face opponents who could tell you every contract you had bid against them and what the result was from memory.

On the other hand, I worked at a US Team Trials championship game, and the two tables were in separate rooms, with a diagonal partition across the table and completely silent bidding. Presumably they wouldn't go through such gymnastics if cheating weren't a concern. Perhaps the stakes are too low at the regional level (or those who are good enough to get away with it quickly progress to a higher level?).