OK guys, here's a method that I found in a forum archive from 2001.
The first step is to choose which of the 3 E/C bets is most likely to repeat.
You can look at the past 10 spins, or whatever, or even change, for instance,
from Color to E/O, or H/L to 'whatever', in mid-session if you choose. Whichever
E/C you choose, bet on a repeat.
The beauty of this system is the progression. If you have won more bets than
you lost and can maintain it, BY EVEN ONE BET, YOU CAN'T LOSE.
Below is a small 10 spin session where if you win 5 out of 10 spins you profit 5 units.
The only rule is +1 on a loss and -1 on a win.
$11 bet to start (Range 11)
W +22
Bet $10
L +12
Bet $11
L +1
Bet $12
W +13
Bet $11
W +24
Bet $10
L +14
Bet $11
L +3
Bet $12
W +15
Bet $11
L +4
Bet $12
W +16
16 - 11 = 5 unit profit even though we only won 5 out of 10 spins.
You can rearrange the W and L any way you want and you still profit 5 units.
The author of this progression also exampled a 21 spin range (first bet $21)
and as long as you do not lose 11 more bets than you win, you profit.
I tested this several times, so far with no losing session.
I used $5 chips, so the first bet is $55. (Range 11)
I just ran another positive test with this.
When I was ahead $55 these numbers hit... 3, 8, 3, 19, 3, 6
How often does that happen?
9 spins later, 22, 22, 35, 21, 5, 35
So I started adding straight bets to the last 4 outcomes. If one hit
I would bet the last 5 outcomes and some connecting corners and
splits.
I don't think repeats within 4-5 spins happen often enough to warrant
playing them as a stand-alone system because you would need a
progression after about 8 losses.