I don't need to back 3 horses. One is enough.
If you back 3 horses per race, in the 25% of races where none win you lose triple the amount! pass on that.

If you back 3 per race, and the avg winner is only $4 that's only a break-even situation based on a strike rate of 75%.

The only way for this to be profitable would be if your avg dividend was higher, whilst still maintaining the strike rate at 75%.

I'd rather pick 1 and have a strike rate of less than 50%.