Simplify the following text for a Grade 7 native English-speaking person.
Original: With John Rauch ( Davis 's hand-picked successor ) as head coach , the Raiders won the 1967 AFL Championship , defeating the Houston Oilers 40-7 .
Simplified: When Al Davis came in as head coach and general manager , the Raiders improved . Davis hired John Rauch and went to the their first AFL Championship against the Houston Oilers and won it 40-7 .