You're confused on the meaning of discretionary. If a strategy can be coded, it is not discretionary. If it is discretionary, that means it can't be coded. At least until AI is invented.Quote from Dhalsim:
Lol the strategy to the human mind is quite simple but to code it was a pain in the ass - it ended up being very complex and difficult but it taught me pretty much that any discretionary type trading can be coded as long as enough time and effort is taken (as well as skill).