Its tough to find 1 system that fires out plays several times a day. I don't have a preference. I have 7 NCAA systems, around 40 NBA, 15 or so NHL, and around 10 MLB. Some NBA angles will overlap.
For example, I have angles that have scheduling filters of 4 in 5 days, 5 in 8 days, 6 in 9 days, and 6 in 10 days. Obviously some of these will trigger for the same game.
I have some angles that occur much more frequently than others. As long as the win percentage is profitable, it doesn't matter to me how often they occur.
They key for me is to not get discouraged after a losing day. The numbers will bear themselves out, you just have to trust ~~the.~~the numbers.