Depends on your definition of 'system', I reckon there are probably many differing opinions as to what exactly one is.

So I will kick it off - I produce my own ratings & with the application of a few tweaks with regards to actual price, produce a set selections that without any filters are profitable, add a few simple filters & away we go - so is this a 'system'? spose so although I don't look at it that way as it's been too much hard work & time in development to classify it as such.

I don't believe there are any strictly mechanical systems such as 'hno1, last start 7 days, 59.0kg, barrier <5, etc etc' that are feasible, but defend the right of those that wish to speculate on them.

__________________
"Now let me get this straight - Whatever I do don't bet this horse?"