Question for the system bettors here.
Say for a example you are running multiple systems. For one race on the days card your systems throw up 3 selections for that particular race. Looking at the odds on offer, one is odds on and the others are in the $4-$5 price range. Do you back all 3 as the systems are all independant of each other. Or do you back only the longer two, reason being if you back the odds on runner as well, even if it wins, you will have lost on the race itself.

Also, lets say all three of these systems have a Sr of 25%, to calculate your odds of winning on that race regardless of price, is it simply adding the percentages together? So in theory there is a 75% of one of the selections winning?