The September 15, 2003 episode of Hollywood Squares (with Tom Bergeron) is the sixth episode of season 6 and it's also the first episode to have a best-two-of-three match format.
For the original season six episodes only (minus theme weeks), Hollywood Squares brought back the best-two-of-three match format with each game being worth $1,000. First person to win 2 games wins $2,000 and automatically advances to the bonus round. That means matches can (and often) straddle episodes.
The "nine keys" bonus round from season 5 stays the same in season six, but with a new prize structure.
The new prize structure for season six is as followed:
1. Vacation (worth over $10,000)
2. $10,000 cash
3. Luxury car (worth over $40,000)
4. $25,000 cash
5. Trip around the world.