▁a ▁previously ▁described ▁winning ▁£ 1 0 ▁Yan kee ▁with ▁w inners ▁at ▁ 1 - 3 , ▁ 5 - 2 , ▁ 6 - 4 ▁and ▁Ev ens ▁has ▁returns ▁calculated ▁by : ▁ ▁£ 1 0 ▁× ▁[( 1 / 3 ▁+ ▁ 2 ) ▁× ▁( 5 / 2 ▁+ ▁ 2 ) ▁× ▁( 6 / 4 ▁+ ▁ 2 ) ▁× ▁( 1 / 1 ▁+ ▁ 2 ) ▁− ▁ 1 ▁− ▁[( 1 / 3 ▁+ ▁ 1 ) ▁+ ▁( 5 / 2 ▁+ ▁ 1 ) ▁+ ▁( 6 / 4 ▁+ ▁ 1 ) ▁+ ▁( 1 / 1 ▁+ ▁ 1 )] ] ▁= ▁£ 9 9 9 . 1 6 ▁ ▁In ▁effect , ▁the ▁bet ▁has ▁been ▁calculated ▁as ▁a ▁L ucky ▁ 1 5 ▁minus ▁the ▁singles . ▁Note ▁that ▁the ▁total ▁returns ▁value ▁of ▁£ 9 9 9 . 1 6 ▁is ▁a ▁pen ny ▁higher ▁than ▁the ▁previously ▁calculated ▁value ▁as ▁this ▁quick er ▁method ▁only ▁involves ▁round ing ▁the ▁final ▁answer , ▁and ▁not ▁round ing ▁at ▁each ▁individual ▁step . ▁ ▁In ▁algebraic ▁terms ▁the ▁O M ▁for ▁the ▁Yan kee ▁bet ▁is ▁given ▁by : ▁ ▁O M ▁= ▁( a ▁+ ▁ 1 )( b ▁+ ▁ 1 )( c ▁+ ▁ 1 )( d ▁+ ▁ 1 ) ▁− ▁ 1 ▁− ▁( a ▁+ ▁b ▁+ ▁c ▁+ ▁d ) ▁ ▁In ▁the ▁days ▁before ▁software ▁became ▁available ▁for ▁use