You let the first 37 spins pass without betting.
From now on, you use a ROLLING WINDOW comprised by the last 37 spins.
This means on each new spin incoming number is added and number in the 38th position (38 spins back) is discarded. You always consider the latest 37 spins only.
Your bet is comprised by every unhit NEIGHBOR number in the spin window.
This is a Wheel-based bet, hence you need to use wheel layout.
Vic