user: ### NOW ANSWER:
Question: What is the average Matches, when Round is Third Qualifying Round?
Columns: ['Round', 'Date', 'Matches', 'Clubs', 'Prize money']
Types: ['text', 'text', 'real', 'text', 'text']
Sample row: ['Extra Preliminary Round', '28 August 2004', 73.0, '661 → 588', '£500']
SQL:

assistant: SELECT AVG("Matches") FROM "Table" WHERE "Round" = 'Third Qualifying Round';