Alydar won the early cheers in a blatant scene-stealer yesterday during the Parade of the post with his rider, Jorge Velasquez. He broke away from the rest of the field of seven and went into a frisky gallop toward the starting gate. The deep devil red of Calumet was easy to spot and there was throaty acclaim for the Preakness' second choice from the biggest crowd (81,261) to gather at Pimlico.

Alydar and Velesquez Peaked too soon. A few minutes later when the favorite, Affirmed, was within easy hailing distance during most of the stretch run, Alydar was no match, again, for the colt that had licked him in the Kentucky Derby.

At the finish, they called it a neck margin. It was more like a half-length, but who's counting things like that now that Affirmed has a Preakiness to go with his Derby?

What Affirmed did in that stretch run was to throw a record-tying last three-sixteenths of a mile at Alydar's bid to gain ground. And what Affirmed had on his back was this generation's riding champ, Steve Cauthen, who was scrubbing and urging while getting into perfect rhythm with the colt that is unbeaten this year.

This time, no excuses for Alydar, whose fault in the Derby was that he was a lollygagging 17 lengths to the rear of Affirmed midway of that race. But yesterday, with a full half-mile to go, Alydar was hustled to within two lengths of the front-running favorite. And coming from the outside a quarter mile from home, he seemed to have hooked Affirmed and perhaps this Preakness with his.

It wasn't, because Affirmed was not taking kindly to being passed, and he was giving Cauthen all the run that rider asked for. And for Alydar, no shame whatsoever. His greatness is but a tad off that of the newest wonder colt, whose 1:54 2/5 for the mile and three-sixteenths was barely two-fifths slower that Canonoro's record for the 103-year-old race.

Believe it, of course, was third. And he was part of the story again today, because Louis Wolfson's colt Affirmed was repeating the tactics he used to lick 'em all in Kentucky two weeks ago.

He was content to let a long shot, Track Reward, set the early pace. Then, as in Kentucky, he killed off the early speed and went to the front. Believe it, as usual, took the first shot at him, going into the far turn. But Believe It could only fire and fall back, again. Some clucking by Cauthen put that challenger away.

Now it was Alydar moving up to striking position. What to do about that?

"I was always looking for Alydar," Cauthen said, "and knew he was after me. And my colt was telling me it wasn't going to be any different than it was in the Derby."

The Pimlico track was under siege as early as 2 a.m. when a vanguard of more than 200 fans showed up. They bivouacked outside the closed gates for the rest of the night after getting a 17-hour head start on the Preakness.

There was quick evidence that the crowd was going to threaten, if not eclipse, the record throng of 77,346 that showed last year for the Seattle Siew Preakness. And they had come to play - the horses, that is. So heavy-handed was the wagering on the first three races that the betting action was more than $100,000 ahead of last year's at that point.

Ninety minutes before the Preakness field of seven went to the post, a new truth was apparent. None of this stuff about Affirmed going of as a 4-to-5 shot with Alydar at 7 to 5 as a re-respected second choice. In a sudden surge of Remembrance of Things Past there was an almost total recall of how Affirmed put away bith Alydar and Believe It in the Kentucky Derby two Saturdays ago.

Now, the mutuel action was showing that Affirmed had such a grip on the fans' respect that the price against him was 2 to 5. You could now get a fat 5 to 2 against Alydar, with Believe It at 6 to 1.

Affirmed, Alydar and Believe It all have bright chestnut coats, and so do two others in the seven-horse field. This was pretty weighty evidence that this Preakness was not going to be won by a horse of another color.

The popularity of Preakness was indicated in another announced figure. Management issued 651 press passes compared to the more 536 last year. This led one of Pimlico's flacks, who begged to remain nameless, to observe, "More frauds in the press box than ever."

An unusual plug for second-choice Alydar was voiced Friday night by Charlie Rose, his exercise rider who has spent more time on Alydar's back than Jorge Velasquez or his other riders combined.

"Alydar is the most intelligent horse I've ever ridder," Rose said. "You know, a race horse actually doesn't know one person from another, but Alydar can pick out his friends in the crowd."

As if to balance the prerace touting, TV commentator Eddie Arcaro, who used to ride the world's best horses, vowed that "Affirmed has everything. He not only can run on the lead, but he comes from off the pace." Another thing. Arcaro said, "He gets you out of the gate in a hurry, with not trouble. That's awfully important to a rider."