In previously mentioned example, say that without a doubt $18 to win on the 4-5 horse (A) and $20 to win on the 6-5 horse(B). If horse A wins you will receive 10 x $3.80 = $38.00. If horse B wins you get 9 x $4.20 = $37.20. Since your initial investment is $38 the wager is at best a clear stage even bet with horse A and then a slight loss with Horse B as compared to the eventual victorious one.