user: Question: Tell me the average points with tyres of B and chassis of TF109
Columns: ['Year', 'Chassis', 'Engine', 'Tyres', 'Points']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [2002.0, 'TF102', 'Toyota V10', 'M', 2.0]
SQL:

assistant: SELECT AVG("Points") FROM "Table" WHERE "Tyres" = 'B' AND "Chassis" = 'TF109';