Bhagwan, what is the reason for targeting TAB number 7? Do you look at all types of races including Set Weights?

Mark, I have been using something similar to your Strike Rate method. I will not lay any horse that has a 10% or higher strike rate and I also consider the Place strike rate, the barrier draw and DFS rankings. I've found that the lower Class races are the most difficult because many of the fancied horses have a less then 10% s/rate, but when combining the aforementioned three factors I have not yet (fingers crossed) encountered an accident.