Doomben Funny you should mention the simple system of "Back all horses who have won at their last 3 starts – irrespective of the course".
I've been playing around with this on midweek selections as a potential laying system. While I don't have alot of midweek data yet to play with it certainly seems horses that have won their last 3 are undervalued.
Bhagwan, would you be able to run this if you have the time?