One thing i do is this with place bets, works a treat.

1 unit place,.....loss
3 unit place,.....loss
9 unit place,.....1.6

now,

out is 13,
in is 14.5

so,

take the 13 units and put it back in the pocket, now with the profit bet all up race to race, that way if you win a few in a row, you would be surprised.

i have done this heaps of times and managed 8 place bets in a row often, if your average div is 1.5,...

10 x 1.5 (5 up)

take out 10.(now nothing to loose !)
5 x 1.5=7.5
7.5 x 1.5=11
11 x 1.5=16
16 x 1.5=24
24 x 1.5= 36
36 x 1.5=54
54 x 1.5=81
81 x 1.5=121
now thats 9 in a row, if you decide to start with a larger start bank, the profits are greater,......got to get the place "winners" but.

sometimes as you state you will get a 2 divie, this is when it works a treat.
Often ill take say 50 units out and all up the rest, that way if you loose, your still up 50 !

Cheers Ding