▁playing ▁using ▁I MP s , ▁a ▁game ▁should ▁be ▁bid ▁with ▁a ▁ 3 8 ▁percent ▁chance ▁when ▁vulner able , ▁but ▁only ▁bid ▁a ▁ 4 6 ▁percent ▁game ▁when ▁not ▁vulner able . ▁This ▁adjust ment ▁sh ifts ▁the ▁Z P ▁required ▁for ▁game ▁and ▁sl am ▁one ▁point ▁down ▁when ▁vulner able ▁or ▁not ▁vulner able . ▁ ▁B idd ing ▁levels ▁and ▁Zar ▁Point ▁requirements ▁Once ▁adjust ments ▁have ▁been ▁made , ▁an ▁opening ▁hand ▁requires ▁ 2 6 ▁Z P ▁and ▁a ▁respond ing ▁hand ▁needs ▁ 1 6 ▁Z P ; ▁a ▁major ▁suit ▁game ▁requires ▁ 5 2 ▁Z P , ▁a ▁small ▁sl am ▁requires ▁ 6 2 ▁Z P ▁and ▁a ▁grand ▁sl am ▁requires ▁ 6 7 . ▁ ▁B idd ing ▁levels ▁are ▁five ▁points ▁apart ▁yield ing : ▁Two ▁level ▁– ▁ 4 2 ▁i . e . ▁ 2 6 ▁+ ▁ 1 6 ▁Three ▁level ▁– ▁ 4 7 ▁Four ▁level ▁– ▁ 5 2 ▁Five ▁level ▁– ▁ 5 7 ▁Six ▁level ▁– ▁ 6 2 ▁Seven ▁level ▁– ▁ 6 7 ▁ ▁This ▁scale ▁does ▁not ▁need ▁to ▁be ▁memor ized . ▁To ▁arrive ▁at ▁the ▁expected ▁number ▁of ▁tr icks , ▁one ▁need ▁only ▁subtract ▁ 2 ▁Z P s ▁and ▁divide ▁by ▁ 5 . ▁ ▁For ▁example , ▁with ▁ 5 2 ▁Z P s , ▁subtract ing ▁ 2 ▁gives ▁ 5 0 , ▁and ▁div iding ▁ 5 0 ▁by ▁