It is about looking for the leaders in 149 spins, but in sections:
Section 1
1 to 37 - numbers that come out 3 or more times.
Section 2
1 to 74 - numbers that have come up 4 or more times.
Section 3
1 to 111 - numbers that have come up 5 or more times.
Section 4
1 to 149 - numbers that have come up 6 or more times.
The numbers are collected then in the end you bet on all, flat for 37 spins.
(Recollection by "Chavezfigueroa")
Note: Unlike the original method that aimed at betting purely flat, a variation with a conscious MM looking at the bankroll and dynamically adapting as spins go by can improve Manucher's hot numbers.