one ▁b ids ▁den oting ▁length ▁in ▁a ▁suit . ▁Art ific ial ▁systems ▁typically ▁reserve ▁at ▁least ▁one ▁one - level ▁suit ▁opening ▁bid ▁for ▁special ▁purposes , ▁un related ▁to ▁the ▁suit . ▁ ▁Natural ▁systems ▁Natural ▁systems ▁generally ▁use ▁opening ▁b ids ▁as ▁follows : ▁A ▁bid ▁of ▁ 1 ▁or ▁ 1 ▁shows ▁at ▁least ▁ 4 ▁or ▁ 5 ▁cards ▁in ▁the ▁major ▁suit , ▁and ▁ 1 ▁or ▁ 1 ▁shows ▁at ▁least ▁ 3 ▁or ▁ 4 ▁cards ▁in ▁the ▁minor ▁suit . ▁The ▁complete ▁hand ▁usually ▁contains ▁about ▁( 1 1 ) 1 2 - 2 0 ( 2 2 ) ▁high ▁card ▁points . ▁As ▁between ▁two ▁major ▁su its ▁or ▁between ▁two ▁minor ▁su its , ▁the ▁bid der ▁opens ▁in ▁the ▁longer ▁suit ; ▁with ▁equal ▁lengths , ▁the ▁higher ▁ranking ▁suit ▁is ▁usually ▁chosen . ▁If ▁the ▁opening ▁bid ▁of ▁ 1 ▁or ▁ 1 ▁promises ▁ 5 ▁cards , ▁the ▁system ▁is ▁referred ▁to ▁as ▁a ▁" five - card ▁major " ▁system ; ▁otherwise , ▁it ▁is ▁referred ▁to ▁as ▁a ▁" four - card ▁major " ▁system . ▁The ▁term ▁five - card ▁maj ors ▁implies ▁that ▁an ▁opening ▁bid ▁in ▁a ▁minor ▁suit ▁bid ▁might ▁show ▁three ▁card ▁length ▁only ▁( for ▁example , ▁the ▁hand ▁pattern ▁might ▁be ▁ 4 = 4 = 2 = 3 , ▁so ▁neither ▁major ▁suit ▁is ▁long ▁enough ▁to ▁show ▁with ▁an ▁opening ▁bid ). ▁A ▁bid ▁of ▁ 1