user: Question: What was the margin of victory when runner-up was K. J. Choi?
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, 'Oct 15, 1995', 'Las Vegas Invitational', '67-65-65-67-67=331', '–28', '1 stroke', 'Billy Mayfair']
SQL:

assistant: SELECT "Margin of victory" FROM "Table" WHERE "Runner(s)-up" = 'K. J. Choi';