user: Question: Who won the game on May 21?
Columns: ['Date', 'Winning Team', 'Score', 'Winning Pitcher', 'Losing Pitcher', 'Attendance', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['May 20', 'Texas', '7–3', 'Kenny Rogers', 'Brandon Backe', 38109.0, 'Arlington']
SQL:

assistant: SELECT "Winning Team" FROM "Table" WHERE "Date" = 'May 21';