Table: golf_results_11
Columns: date
tournament
winning_score
margin_of_victory
runner_s_up

Question: When was the winning score −9 (72-68-64-67=271)?
SQL: SELECT "date" FROM golf_results_11 WHERE "winning_score" = '−9 (72-68-64-67=271)'

Question: What was the margin of victory for the Mississippi Gulf Resort Classic?
SQL: SELECT "margin_of_victory" FROM golf_results_11 WHERE "tournament" = 'mississippi gulf resort classic'

Question: What was the margin of victory when Mark Calcavecchia was the runner-up?
SQL: SELECT "margin_of_victory" FROM golf_results_11 WHERE "runner_s_up" = 'mark calcavecchia'

Question: What was the date of the Ace Group Classic tournament with a 1 stroke margin of victory?
SQL: SELECT "date" FROM golf_results_11 WHERE "margin_of_victory" = '1 stroke' AND "tournament" = 'the ace group classic'

Question: What was the margin of victory when the winning score was −9 (72-68-64-67=271)?
SQL: SELECT "margin_of_victory" FROM golf_results_11 WHERE "winning_score" = '−9 (72-68-64-67=271)'