actually you can drop the SP filter and get this:
Test your Horse Racing System - Results

Below are the results of your system. If you were testing Laying it is against the higher price available. if you test betting its agaisnt the lower available value on betfair.

There were 26612 horse form lines in the database at this point in time. We update when we get time.

There were 45 selections for the System
There were 20 Winners for the System for a strike rate of 44.44%
There were $57.45 returned for WIN (after 5% commission) which means a Profit or loss of $12.45 or a percentage profit/loss of 27.67%
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i dislike price filters because in the real world they can be a real pain - what i mean is who wants to sit there all day waiting for something to go from 9.9 to 9.80 for example and then the other question is what tote do you take etc.
i find life much easier when i leave them out.