user: Question: What was the margin of victory when the winning score was −9 (72-68-64-67=271)?
Columns: ['Date', 'Tournament', 'Winning score', 'Margin of victory', 'Runner(s)-up']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Feb 14, 2010', 'The ACE Group Classic', '−17 (68-67-64=199)', '1 stroke', 'Tommy Armour III']
SQL:

assistant: SELECT "Margin of victory" FROM "Table" WHERE "Winning score" = '−9 (72-68-64-67=271)';