user: Question: What is Tournament, when Margin is Victory of 6 strokes?
Columns: ['Date', 'Tournament', 'Winning score', 'Margin of victory', 'Runner(s)-up']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['12 Dec 2004', 'Dunhill Championship 1', '–7 (71-69-70-71=281)', 'Playoff', 'Neil Cheetham']
SQL:

assistant: SELECT "Tournament" FROM "Table" WHERE "Margin of victory" = '6 strokes';