This is something I've been looking at for a couple of days and its been doing ok. I've had draw downs, but it always recovers. It may be a flash in the pan, but I thought I'd put it out there.
It's probably, like many methods, been done many times before, but here goes.


Quite simply, when 2 unique numbers from a line, or double street, appear in the last eight spins, bet the other 4 numbers.
That's it.


I carry on betting using a progression, even when they drop out of the eight and even when others qualify.
In Mr. J's street system, when numbers dropped off the marquee, or when other numbers appeared, he changed his bet. With this, I don't.


During the course of the betting, other qualifying lines show. Bet these too, again with a progression.
Sometimes, you can be betting on up to 5 groups of 4 numbers, at different stages of the progression. 
When a hit occurs, stop betting the number group, unless the number that just hit has created another qualifying group.


Another thing I've been doing is only using the last spin and one other to qualify a line. I'll post an example.


It's very simple really. You can end a session when in profit, play hit and run, whatever.
This is the way I've been playing it.
There is no scientific reason behind any of the rules and there is probably a better way to play this, but the above method has been my starting point.


The progression I use is
1 unit for 8 spins
2 units for 4 spins
3 units for 3 spins
5 units for 2 spins
6 units for 1 spin
7 units for 1 spin
8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 25, 28, 32, 36, 40, 45 all for 1 spin.
The highest I've seen during testing is 20 and I realize that this number will scare people off!




An example:


36
20
11
25
33 first trigger. Bet 31, 32, 34, 35
25
11
5
33
5
28 another trigger. Add 26, 27, 29 and 30 to betting ( at different stage of progression)
3 another trigger. Add 1, 2, 4 and 6
13
28
6 W stop betting this group of numbers
22
14 trigger. Add 15, 16, 17 and 18
16 W stop betting this group
26 W and another trigger. Add 25, 27, 29 and 30
21 trigger. Add 19, 20, 23 and 24
32 W stop betting this group
18
4
19 W and another trigger. Add 20, 22, 23 and 24
34 trigger. Add 31, 33, 35 and 36
3 trigger. Add 1, 2, 5 and 6
6 W stop betting this group
22 W and another trigger. Add 20, 21, 23 and 24
0
14
32
29 W stop betting this group
3 trigger. Add 1, 2, 4 and 5
21 W and another trigger. Add 19, 20, 23 and 24
3
26 trigger. Add 25, 27, 28 and 30
25 W stop betting this group


This was an actual session.
Hope this is clear enough.


Cheers.

a session i've just had on dublinbet:-
6
4 trigger 1,2,3,5
25
36
32 trigger 31,33,34,35
19
27 trigger 26,28,29,30
21 trigger 20,22,23,24
4
29 W stop betting this group
30
28
23 W stop betting this group
34 W stop betting this group
32 trigger 31,33,35,36
4
2 W and trigger 1,3,5,6
8
34
17
0
23
8
20 trigger 19,21,22,24
24 W stop betting this group
1 W stop betting this group
26
16
10 trigger 7,9,11,12
29 trigger 25,27,28,30
0
32
21
13 trigger 14,15,17,18
6
36 W and trigger 31,33,34,35
17 W and trigger 14,15,16,18
17
9 W stop betting this group
36
33 W and trigger 31,32,34,35
27 W
end session.

another quick session, with excellent results

4
25
35
23
19 T 20,21,22,24
30 T 26,27,28,29
22 W
6 T 1,2,3,5
36 T 31,32,33,34
1 W and T 2,3,4,5
15
10
24 T 19,20,21,23
16 T 13,14,17,18
13 W
3 W and T 2,4,5,6
25
31 W
5 W and T 1,2,4,6
4 W
4
14 T 15,16,17,18
29 W and T 27,27,28,30
19 W
4
9
28 W and T 25,26,27,30
4
36
25 W
10 T 7,8,11,12
12 W
16 W