Ok so I placed 2 small bets over the weekend. I was using skybet and I chose 5 selections and used their automatic 5x trebles so I assumed that would cover all angles, if 3 or more came in I'd get a return. I now realise it would require 10 bets to cover all angles but I still can't understand this..

3 out of the 5 won on Saturday and I got a return, less than my bet which I expected but then I placed that on another 5 games on Sunday.. 4 out of the 5 won and I got nothing.

I'm struggling to understand how this works, can anyone explain it to me? Also why don't they automatically do a 10x trebles if that's what it takes to cover them all, how do they choose which 5 trebles to make?