Clayton's five greatest NFL rivalries

When I started covering the NFL in the 1970s, I was fortunate enough to learn football while covering the Pittsburgh Steelers. Being around the Steelers, you learned defense, running the football and rivalries.

Every time the Steelers played the Oakland Raiders, the hitting was incredible and the storylines were plentiful. It was football at its best. Now, a new rivalry is building between the San Francisco 49ers and the Seattle Seahawks.

Where does it rank in my history database? Here are my top five rivalries:

1. Oakland-Pittsburgh, 1970s: The only thing that prevented Al Davis' Raiders from becoming a dynasty was the Steelers and Chuck Noll. It was the ultimate rivalry. They bashed each other on the field and carried the battle off the field. No rivalry measured up to the Steelers versus Raiders.

2. San Francisco-Dallas, 1980s and '90s: For more than a decade, big games in the NFC always seemed to revolve around America's Team and the 49ers. Bill Walsh put together one of the greatest dynasties in the NFC. The Cowboys were always in the big game. The best was when Deion Sanders moved from San Francisco to Dallas in 1995 and earned a Super Bowl ring.

3. Baltimore-Pittsburgh, 2000s: Once Ray Lewis was drafted by the Ravens, they were established as the perfect counterpunch to the Steelers. Games were low-scoring and close. Hitting and talking were at the max.

4. San Francisco-Seattle, current: Pete Carroll and Jim Harbaugh carried over a great Pac-10 rivalry to the NFL. Both coaches stress big, physical teams that love to hit. Both teams love to talk. During the offseason, once the Seahawks make a move, the 49ers usually counter, and vice versa.

5. Chicago-Green Bay, forever: The rivalry has been relatively quiet of late, but it's always been good. When Lovie Smith took the job as coach of the Bears in 2004, he said his mission was to beat the Packers.