user: Question: Who had highest assists at game on December 21?
Columns: ['Game', 'Date', 'Team', 'Score', 'High points', 'High rebounds', 'High assists', 'Location Attendance', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [18.0, 'December 1', 'Minnesota', 'W 100–86 (OT)', 'Shawn Marion (16)', 'Tyson Chandler (18)', 'Jason Terry (7)', 'American Airlines Center 19,567', '14–4']
SQL:

assistant: SELECT "High assists" FROM "Table" WHERE "Date" = 'December 21';