user: Question: What is the round with Ajax opponents
Columns: ['Season', 'Round', 'Opponents', 'Home leg', 'Away leg', 'Aggregate']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1991–92', '1', 'Ajax', '0–1', '0–3', '0–4']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Opponents" = 'Ajax';