user: Question: What round was a Loss with a record of 12-3?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Loss', '13-5', 'Anthony Ruiz', 'KO (punches)', 'Pure Combat 9', '3']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Res." = 'Loss' AND "Record" = '12-3';