开叫2c可以是18个半赢顿的长套牌，也可以是22点以上的均型牌。点力不够开叫2c的条件是：快速赢顿要>=4，并且快速输顿<=4,也就是快速赢顿要大于快速输顿。
快速赢顿 ：the number of tricks you expect to win in a suit on the first two rounds

ak=2,aq=1/2,a=1,kq=1,kx=1/2

• 2C-2D: waiting
  
• 2C-2D-2NT: 22-24, 没有走2h relay, 后续可用mpuupet问高花
  
• 2C-2D-2S-3C: double negative
  
• 2C-2D-3C-3D: double negative, 2C-2D-3C-3D-3H/3S: forcing one round (new suit), responder pick one suit
  
• 2C-2D-3D-3H: 应叫人也许有5张红心，也许没有，等待开叫人下一步叫牌，应叫人的牌力或者牌型不适合叫3nt
  
• 2C-2D-3D-3NT: 应叫人<=6p,对方片没有三张支持
  

double negative : <=2Q， 不能有A/K

• 2c-2nt: 10点以上，平均牌型，满贯逼叫
• 2C-3C/3D， 应叫方有六张，套上有两大牌
• 2c-2H/2S: 应叫方有五张H/S,套上至少有两大牌
• 2C-3H/3S: 应叫方有六张H/S,套上至少有两大牌

2C-(something)-pass: GF
2C-(something)-X/XX: double negative

• 2C-2D-2NT: 22-24, 没有走2h relay, 后续可用mpuppet问高花
  

• 2C-2D-2H-2S-2NT: 25-26, Mpuppet stayman and transfer and all system are still ON even though declarer will not be changed

• 2C-2D-2H-2S-3C/3D: 4C+5H/4D+5H， 梅花或者方片4张以上红心五张双套

• 2C-2D-2H-2S-3H/3S: H/S single suit，红心单套

• 2C-2D-2S-2N-3C/3D: S+C/D 梅花或者方片4张以上黑桃五张双套

• 2C-2D-3H/3S: 4 card H/S with 5+D： 5张以上方片4张所叫高花

• 2C-2D-3NT: long minor suit with 9 winning tricks and 18 ish pts

• 应叫方越过2S接力，跳到下一级，转移到最近套 （bypassing the relay - transfer to 6+ broken suit） opener can reject transfer and bid his own suit (GF)

2C-2D-2H-2NT: transfer to C
2C-2D-2H-3C: transfer to D
2C-2D-2H-3D: transfer to H
2C-2D-2H-3H: transfer to S

• 2c-2d-2h-2s-3nt: 27p+

2c-2d-2h-2s-3nt-4c, puppet stayman
2c-2d-2h-2s-3nt-4d/4h, transfer
2c-2d-2h-2s-3nt-4s: minor stayman, 4-4 minors, slam intereste