This is a forced voodoo double street system
Split the DS into odds and evens
1,3,5 are odd DS
2,4,6 are even DS
when 1 of any appears, bet the other 2 DS
it's easier with an example
4 now bet the other two evens: 2,6
5
1 loss -2
3 now bet the other two odds: 1,5
5 win 0
6 now bet the other two evens: 2,4
1
2 win +1
2 now bet 4,6
2
6 win +2
5 now bet 1,3
4
6 loss 0
3 now bet 1,5
1 win +2
Etc
Flatbetting 2 DS essentially, I've done two 100 spin samples so far
Session 1 ended +15
Session 2 ended +17
Lots of swings and roundabouts but no big DD's (yet)
The good thing is, being flat betting you can cut your losses at any time
or indeed choose to leave when just +5 for example
Give it a go!