▁the ▁following ▁odd s ▁might ▁be ▁encountered ▁to ▁represent ▁the ▁true ▁chance ▁of ▁each ▁of ▁the ▁three ▁out comes : ▁ ▁Home : ▁Ev ens ▁Draw : ▁ 2 - 1 ▁A way : ▁ 5 - 1 ▁ ▁These ▁odd s ▁can ▁be ▁represented ▁as ▁imp lied ▁prob abilities ▁( or ▁percent ages ▁by ▁multip lying ▁by ▁ 1 0 0 ) ▁as ▁follows : ▁ ▁Ev ens ▁( or ▁ 1 - 1 ) ▁corresponds ▁to ▁an ▁imp lied ▁probability ▁of ▁ ▁( 5 0 %) ▁ 2 - 1 ▁corresponds ▁to ▁an ▁imp lied ▁probability ▁of ▁ ▁( 3 3 %) ▁ 5 - 1 ▁corresponds ▁to ▁an ▁imp lied ▁probability ▁of ▁ ▁( 1 6 %) ▁ ▁By ▁adding ▁the ▁percent ages ▁together ▁a ▁total ▁' book ' ▁of ▁ 1 0 0 % ▁is ▁achieved ▁( re present ing ▁a ▁fair ▁book ). ▁The ▁book maker , ▁in ▁his ▁wish ▁to ▁avail ▁himself ▁of ▁a ▁profit , ▁will ▁invari ably ▁reduce ▁these ▁odd s . ▁Consider ▁the ▁simplest ▁model ▁of ▁reducing , ▁which ▁uses ▁a ▁proportional ▁decre asing ▁of ▁odd s . ▁For ▁the ▁above ▁example , ▁the ▁following ▁odd s ▁are ▁in ▁the ▁same ▁proportion ▁with ▁regard ▁to ▁their ▁imp lied ▁prob abilities ▁( 3 : 2 : 1 ): ▁ ▁Home : ▁ 4 - 6 ▁Draw : ▁ 6 - 4 ▁A way : ▁ 4 - 1 ▁▁ 4 - 6 ▁corresponds ▁to ▁an ▁imp lied ▁probability ▁of ▁ ▁( 6 0 %) ▁