SELECT "Runner(s)-up" FROM table_40228 WHERE "Margin of victory" = '1 stroke' AND "Tournament" = 'joburg open 1'
What is Runner(s)-Up, when Margin of Victory is 1 Stroke, and when Tournament is Joburg Open 1?
CREATE TABLE table_40228 (
    "Date" text,
    "Tournament" text,
    "Winning score" text,
    "Margin of victory" text,
    "Runner(s)-up" text
)