CREATE TABLE table_77498 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "To par" TEXT, "Margin of victory" TEXT, "Runner-up" TEXT)

What was the to par of the tournament that had Ken Duke as a runner-up?
SELECT "To par" FROM table_77498 WHERE "Runner-up" = 'ken duke'
SELECT "To par" FROM "table_77498" WHERE "Runner-up" = 'ken duke'