NEW YORK -- Only fans of a certain age will remember the fierce (and that might be putting it lightly) rivalry between the New York Yankees and the Kansas City Royals in the late 1970s and early ‘80s.

For those who aren’t familiar, let George Brett sum it up for you:

“Hatred,” Brett said Wednesday while standing in the visitors’ dugout at Camden Yards as the Royals prepared to face the Orioles in Game 2 of the American League Wild Card Series. “Pure hatred. Hatred is probably the key word.”

Sweep secured in Baltimore, the Royals are moving on to face the Yankees in the AL Division Series. The two teams haven’t met in the postseason since 1980, when Brett was an AL MVP in the peak of his Hall of Fame career and the villain of New York.

“It’s going to be awesome,” Brett said. “It’ll be great. I’ll absolutely love it. …

“Some older fans will remember. They’ll be telling their grandkids, saying, ‘You should have seen these two teams play in the ‘70s -- oh my God. This was bad. These guys really didn’t like each other.’ We really didn’t.”

• Royals-Yankees position-by-position breakdown

No, they did not. That much is clear when watching low-definition video from those days, when the Royals and Yankees played each other in the ALCS four times from 1976-1980. There were hard slides and harsh words between two teams who couldn’t have been more different: the old-guard Yanks against the young upstart Royals.

“We really despised each other,” Brett said. “The teams did, the organizations did, and I think the cities did. We’d come to New York and they were just booing, loud and obnoxious and nasty. And then they would come to Kansas City, and I’m sure our fans did the same thing. But it was a rivalry where both teams really got up to play those games, and I think the fan base behind them got up to watch them play.”

Brett enjoys looking back on those days, even though there’s some resentment that the Royals won only one out of those four ALCS showdowns. They finally emerged victorious in 1980 via a sweep.

“That was like winning the World Series,” said Brett, whose team went on to lose to the Phillies in the actual World Series in six games.

In 1976, Brett was in his third full year in the Majors as a 23-year-old. The Royals made the playoffs for the first time in his career -- and the first time in franchise history, which began in 1969. To take the Yankees to five games before eventually losing on Chris Chambliss’ pennant-winning home run hurt, but the Royals couldn’t have asked for a better first experience.

“You’re going up against the Yankees, 6-6 going into the bottom of the ninth inning,” Brett said. “... Yeah, you’re [angry], and you’re down in the dumps, but it was a great experience for a 23-year-old kid playing his first series like that. It was fun. It was great.

“But then to lose the next two years was tough. And in ‘79, we didn’t even make it.”

The Royals won a franchise-best 102 games in 1977 only to fall again to the Yankees in the ALCS in five games. That series really stirred the rivalry. There was Royals outfielder Hal McRae taking out Yankees second baseman Willie Randolph in Game 2 on a slide-turned-body block. McRae and New York’s Cliff Johnson nearly came to blows before Game 4. Graig Nettles slid hard into second baseman Frank White in the Yankees’ Game 4 victory.

So the controversy was thick and the hatred was nearly boiling over when Brett came in hard to third base on a first-inning triple in Game 5. Brett was on all fours, knocking Nettles off the bag, and Nettles lifted his foot and kicked Brett in the face. Brett wasted no time, winding up a punch and connecting.

“I just got up and popped him,” Brett said.

Royals third-base coach Chuck Hiller got into it. Yankees pitcher Ron Guidry got into it. Benches cleared. Madness ensued. A pile formed, and Brett was on the bottom of it.

“All I remember is [catcher] Thurman Munson laying on top of me,” Brett said. “He said, ‘George, don’t worry, no one is going to take a cheap shot at you.’ I thought that was pretty cool. Because I never said anything to Thurman, never had a beer with him or anything. But he said he would make sure no one takes a cheap shot.”

When things calmed down, the game went on. No one was ejected. The Yankees won the pennant, and the World Series, that year and the next. Neither team reached the postseason in 1979, but it was Brett’s three-run home run off Rich Gossage that sealed the Royals’ sweep in ‘80.

“I knew Goose was going to throw something hard,” Brett said after pointing out that U L Washington beating out an infield hit to second base gave him the opportunity against Gossage. “He had a big ego, I had a big ego. I just said, ‘Hey, don’t try to hit a home run. Just try to hit it hard. Be quick.’ And it was one of the farthest balls I ever hit, and probably the most meaningful swing in my career.”

The Royals and Yankees will be playing meaningful baseball again this week. It certainly will not look like the rivalry decades ago. But Brett can’t wait anyway.