In Don von Elsner's "Jake of Diamonds", Jake Winkman is playing in a team-of-four. Each partnership on his team consists of one expert who knows the field well, and one p;ayer who doesn't. In what Jake describes as a "perfectly ethical signal", each expert will signal to his or her partner whether their opponents and their teammates are experts, middling, or lesser players. The information is used to determine how aggressively they play, whether to push for slams, etc. Is this really ethical? Or was it in the 1960s when the book was written?