Well, this probably sounds absolutely stupid but I get a few nice collects out of it, so here goes.

I tend to use this only on big fields (say 14+) or sometimes on the last race of the day (minimum 10 runners). If I have two horses picked out in the race and one of them is starting from either the inside or outside barrier, then I also have a small each-way bet on the horse starting from the other barrier.

For example, in that race today, my top two picks were clearly numbers 9 & 5. Well, number 9 was starting from barrier 1, so I also put a small bet on number 17 which was starting from the outside barrier. That was the only reason I backed it. It's form was absolutely awful. These were the races I used this method on today:

Mackay R8
Top pick: 10 Blue Racer UNP
2nd pick: 2 Captain Kilometre (outside) WON $9.70
Roughie: 12 Special Diam (inside) UNP

Hawkesbury R6
Top pick: 5 Come In Spanner Won $2.30
2nd pick: 8 Mersey Beat (inside) PLA
Roughie: 15 Jonnywoo (outside) UNP

Bendigo R6
Top pick: 9 Maple Spirit (inside) PLA
2nd pick: 5 Hotspurs PLA
Roughie: 17 Brolene (outside) WON $124.30

Geraldton R7
Top pick: 1 Chief O'Hara UNP
2nd pick: 4 Corporate Georgina (outside) UNP
Roughie: 3 Clairside (inside) UNP

By the way, as you can see, I could have had the trifecta in Brolene's race but didn't put one on. I took a quinella instead. Quinella paid a nice $316 but the trifecta was $3870!!!