user: Question: Name the margin of victory when tournament is Algarve Open de Portugal
Columns: ['No.', 'Date', 'Tournament', 'Winning score', 'To par', 'Margin of victory', 'Runner(s)-up']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '27 Sep 1992', 'Piaget Belgian Open', '71-70-64-69=274', '−10', '3 strokes', 'Barry Lane']
SQL:

assistant: SELECT "Margin of victory" FROM "Table" WHERE "Tournament" = 'Algarve Open de Portugal';