At the basic level we start with two:
The Sleeper
Rear naked choke
Lion killer
and
The guillotine
it is important to know the guilloine defence
the best sleeper defence is Sweetcorn
if the geezer is wearing a gi we employ 2 versions of okuri eri jime, the sliding collar choke, and kata ha jime, the shoulder version, creating a total of 5 in the set:
sleeper
guillotine
okuri eri
henka
kata ha jime