Horse racing's followers wage an eternal argument over speed and class, debating whether horses should be judged according to the opposition they beat or the time they run.

Usually, these two ways of interpreting horse races yield fairly similar conclusions. But after the Blue Grass Stakes at Keeneland today, the two camps could not agree on the meaning of Spectacular Bid's victory.

In the eyes of the classifiers, Spectacular Bid did everything he was supposed to do in his final prep for the Kentucky Derby May 5.

He faced a consistent, talented foe in Lot O'Gold, the second-best 3-year-old in Florida this winter, and demolished him by seven lengths. Another good horse Bishop's Choice, finished 15 lengths behind the winner in third place.

But to the speed handicappers, Spectacular Bid's performance seemed astonishingly poor.

Over a racing strip fast enough to have produced a track record, he covered 1 1/8 miles in 1:50. That was the slowest Blue Grass on a nonsloppy track in more than a quarter of a century.

And Spectacular Bid required 13 4/5 seconds to cover the last eighth of a mile, a fraction more typical of cheap claiming horses than the champion of a generation.

The ambiguity of the Blue Grass will prompt extensive study in the days between now and the Derby.

Jockey Ron Franklin was urging Spectacular Bid from the start, but he could not draw abreast of the other three horses in the field at the first turn. So the colt raced wide, losing ground all the way, and he was last when he reached the backstretch.

Spectacular Bid accelerated on the backstretch, as he always seems to do on a straightaway, and had surged to the lead by the time he had traveled a half mile. Lot O' Gold stayed within striking distance around the turn, but when Franklin whipped his mount twice at the head of the stretch, Spectacular Bid began drawing away to a comfortable victory.

Trainer Bud Delp, who is more attuned to the significance of time than most members of his profession, saw the 1:50 on the Teletimer and asked his jockey, "Ron, what do you think?"

"He was playing," Franklin tod him.

"That's just the way I saw it, old buddy," Delp said. Both he and Franklin would maintain that the time was largely irrelevant, that Spectacular Bid could have run much faster had it been necessary.

"This is a horse who needs another horse to be with him for him to do his best," Franklin said. "He moved on his own down the backstretch to make the lead, just playing around and not leveling.

"I just hope Flying Paster is enough horse to pressure Spectacular Bid, because I'd like to see what he can do. If he's pressured enough in the Derby I think he can break the track record."

There was only win betting, and Bid paid $2.10.

Delp admitted he would have been much happier to see Spectacular Bid run unequivocally fast, as he has many times during his 10-race winning streak.

"I'd have liked to see him do 1:46 2/5 with his ears pricking," the trainer said. "I'd have liked to see him gallop out a little stronger. But the colt's getting smart. When he took the lead he thought it was time to relax. But whenever a horse comes to him, he's gone."

The assumption that a horse who wins easily could have run much faster if he were pressed is a common one, but it is often invalid. It is a frequent point of debate between the classifiers and the speed handicappers, who tend to take the final times of races at face value.

In the next nine days, they will do plenty of debating. At the very least, the slow time of Spectacular Bid's race has injected a great element of uncertainty into what appeared destined to be an open-and-shut Kentucky Derby. CAPTION: Picture, Spectacular Bid romps home a seven-length winner in the Blue Grass Stakes with Ron Franklin aboard. The time for the 1 1/8 miles was laggardly 1:50. AP