Today, after slightly less than a year's time, the title of defending NBA champions hangs heavily upon the Los Angeles Lakers. Trailing the Houston Rockets three games to one in the best-of-seven Western Conference final, the team held what was perhaps its last practice of the year at a local college.

The fifth and possibly final game in the series will be played Wednesday night here at the Forum.

For 17 years, no other NBA team has been able to withstand the burden of being the league's champion and repeat the following season. The failure of his team to respond to that challenge infuriates and mystifies Lakers Coach Pat Riley.

"It's something insidious, like a kind of sabotage that takes away a team's strength and power," he said. "It must be something psychological. If we were on our game you wouldn't be seeing the things you're seeing out there. I can sense it. We're not choking, but we need to free our spirit."

Riley, like his Houston counterpart Bill Fitch, long has been a disciple of the mental aspects of professional basketball. But whereas Fitch makes his points with a biting tongue and the seemingly endless repetition of game tape, Riley prides himself on being a motivator, knowing the factors that cause players to respond to certain situations in certain ways.

The challenge of successfully defending the title has been on Riley's mind since the Lakers visited President Reagan at the White House days after winning the 1985 championship. Throughout the regular season, he coached with the playoffs in mind.

"The mental toughness that a team develops over the course of the regular season comes into play particularly at playoff time," he said. "Physically, everyone is going to go above and beyond their normal capabilities."

At the start of the postseason, it appeared Los Angeles had both its mental and physical games down pat. The Lakers dominated in a three-game first-round sweep of the San Antonio Spurs, winning by an average of almost 32 points per game.

It was in the conference semifinals against Dallas that Riley said he began to sense something was wrong. Although the Lakers won four games to two, he said "the wheels were starting to turn."

"I think maybe the closer a team comes to winning it again, the tighter the screws begin to get," he said. "I've been talking to them for a week now, trying to shake them out of it. Maybe they're not listening, maybe listening doesn't help."

All-star guard Magic Johnson said he believes the Lakers have been listening, but perhaps to the wrong voices. "Everyone has been saying that it was going to be the Lakers and the [Boston] Celtics all along, to just throw away the regular season," he said. "It sinks in your mind. Maybe the players read that and say, 'Yeah, that's what it'll be, don't even think about Houston.' I don't know."

But it is looking increasingly as though Houston will be in that final series. Fitch says being on the verge of the championship series isn't enough to make him happy, "but is better than the alternative" of elimination.

At the start of the year, though, there was talk that, given the club's disappointing first-round loss to Utah in last season's playoffs, anything less than a showdown with Los Angeles for the conference crown would lead to changes, beginning with the coach.

"I was never concerned about that. Life is too short to worry about stuff like that," said Fitch. "You can only coach your team and say that the most important game is the next one. If you've got a good team things will take care of themselves. These guys never had a goal for themselves all season."

In hindsight, Riley said that might be the best approach.

"I've seen teams like Boston and Philadelphia win championships and thought that they would become dynasties and then saw them lose the next season," he said. "Perhaps all the things that come from winning does that to you. It divides you mentally. It's an oppressive state. You've got to be so undistracted to win again. I'm starting to sense it in us like I could sense that those teams weren't [undistracted]. Opponents can sense pressure."

The Rockets have responded by playing with a confidence tempered only by the sense that they're a team with nothing to lose.

"This is just fun," said center/forward Ralph Sampson. "CBS is here, everyone is watching, the games are great -- just being in this situation is fun."

Sampson's pleasure has no doubt been enhanced by the presence of teammate Akeem Olajuwon, who has averaged 31 points, 12 rebounds, four blocked shots and two assists per game during the series. But those numbers, as dominant as they are, fail to portray the full picture, said Riley.

"He's been wonderful but he's only done his job," he said. "It's everyone else that has come through in pressure situations. That's been the tough part."

Now it's incumbent upon the Lakers, the defending champions, to respond to perhaps the ultimate pressure situation.