user: Question: What is the round when the opponent is Andre Roberts?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Win', '6-12', 'Johnnie Brown', 'Decision', 'XFC 1 - Xtreme Fight Club 1', 'N/A']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Opponent" = 'Andre Roberts';