Smith Echo - folksbridge21/system2 GitHub Wiki

Smith Echo - Used when opponents are playing a Notrump contract, a discard signal indicating attitude of partner's opening lead. The discard signal is provided by the partner of the leader at the first opportunity, typically after declarer has won the trick. The play of a low spot card signals a discouragement while a high card provides a positive signal to continue the suit of the opening leader.

搭档无将首功后，对庄家出牌的第一张垫牌表示对搭档套的喜好。大牌表示搭档进手后继续功，小牌表示不鼓励。

reverse smith echo是相反 对庄家出牌的第一张垫牌,小牌表示欢迎搭档进手后继续功，大牌表示不鼓励。