This classic roulette strategy by Jacques Inaudi originally is called
1:6 changing game with combined plus-minus-progression
(German: 1:6 Wechselspiel mit kombinierter Plus-Minus-Progression)
It waits for series of 3 times the same color,
or a 3 times changing phase.
Then it bets on its continuation.
The historic original System description in German language.
step tree
As usual for pattern strategies, a step tree is useful to build the Inaudi Wechselmarsch:
X1
/R B\
X2 X9
/R \B /R \B
X3 X8 X10 X11
/R \B /R \B /R \B /R \B
.12 X4 :16 X5! X7! :16 X6! .12
. /R B\ . . .
. :16 X5 : : .
. /R \B
: X6 .12
/R B\ .
X7 :16 .
/R B\ .
.12 X4! :
.
.
Xy = step, y = number, Xy! = existing step
R = Red, B = Black
. . . = bet the series
: . : = bet the changing series