question: When is the winner olympiacos, the venue is georgios karaiskakis stadium and the runner-up is iraklis?
answer: SELECT year FROM table_name_12 WHERE winner = "olympiacos" AND venue = "georgios karaiskakis stadium" AND runner_up = "iraklis"
context: CREATE TABLE table_name_12 (year VARCHAR, runner_up VARCHAR, winner VARCHAR, venue VARCHAR)