CREATE TABLE table_39482 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "Margin of victory" TEXT, "Runner ( s ) -up" TEXT)

What was the margin of victory when the winning score was 12 (66-67-64-71=268)?
SELECT "Margin of victory" FROM table_39482 WHERE "Winning score" = '−12 (66-67-64-71=268)'
SELECT "Margin of victory" FROM "table_39482" WHERE "Winning score" = '−12 (66-67-64-71=268)'