Can anyone tell me the difference? because they seem to me to be the same thing.
The Olram Subtlety is a false count with cards developed by Ed Marlo (Olram is Marlo backwards) that show all cards are the same when in fact half are different.
First description in The New Tops, Vol. 5, N° 11, november 1965.
Used in the popular card effect Eight Card Brainwave.
The Flushtration Count, also known as the Back Count, is a card display that show all cards are the same when in fact they can be all different.
It was popularized by Brother John Hamman in his trick "Flushtration", marketed by Abott's in 1969.
The principle is of undiscovered origin as noted by Norm Houghton in Ibidem, No. 1, June 1955.
Best regardz
Dom Kabala.