BALTIMORE - Horse racing's long wait for its next superstar, the horse capable of ending the Triple Crown drought, will last at least one more year.

When next spring arrives, it will have been 34 years since Affirmed won three duels with Alydar in 1978 to become the 11th horse to sweep the Kentucky Derby, Preakness Stakes, and Belmont Stakes.

Affirmed was great, but he was also the third Triple Crown winner in the space of six years, so the hoopla wasn't as loud as it will be for the next horse to follow his lead. If it happens.

Animal Kingdom, the winner of this year's Kentucky Derby, made a great effort in Saturday's Preakness but was unable to catch Shackleford, a speed horse who was near the lead from the start and built up too wide a margin to overcome.

Shackleford, who also set the pace in the Derby but couldn't sustain that lead, held on for the half-length victory Saturday, shutting the door on Animal Kingdom's bid for immortality.

It was a combination of things that ended the Triple Crown search this year. Animal Kingdom jumped at the start and trailed the field badly by the time he gathered himself. Jockey John Velazquez had to fight the horse to keep him running. Animal Kingdom didn't like the spray of dirt that kept hitting him in the face for one thing, and the torrid early pace had him far off the lead.

After three-quarters of a mile in the 13/16-mile race, Animal Kingdom was still in 12th place, nearly six lengths off the lead. He closed masterfully, but the race ended about 50 yards too soon for him.

So, better luck next year, and the chorus that maintains the Triple Crown series is too difficult will continue to defend that position. Horses are barely teenagers as 3-year-olds, and the pounding that goes into training for the distance and then getting through the prep race season takes its toll. Running three major stakes races in the space of five weeks is not suited to the modern horse that is bred for speed and not endurance.

Maybe the series could be spread out. Maybe it could be run for 4-year-olds. Neither of those will likely happen because horse racing loves its traditions. And someday some horse will beat all of those odds again.

"It's a difficult task, running three distance races in five weeks at three different tracks. It takes a super horse to accomplish it," Shackleford trainer Dale Romans said. "There will be another Triple Crown winner. I don't think it should be messed with at all. When that super horse comes along, he'll accomplish it."

Well, maybe. But not this year.

"I would love to win a Triple Crown, as much for me as for everybody else," said Graham Motion, trainer of Animal Kingdom. "There is so much pressure to do that because it would be so good for the game. But it wasn't meant to be. The horse ran a great race. He did nothing wrong. If it wasn't a Triple Crown race, you'd be thrilled that he ran so well."

He did run well, although not well enough to catch a horse that had never won a graded stakes race and had only two previous wins in six lifetime starts.

Shackleford didn't originally qualify for entry into the Derby, but got in when defections because of poor performance and injury opened a spot for him.

Saturday's outcome further confirms the suspicion that this season's crop of 3-year-olds will not go down as a great class. Some of the better horses didn't make it soundly to the Kentucky Derby and some of the other contenders - notably Florida Derby winner Dialed In and Santa Anita Derby winner Midnight Interlude - have not hit the board in the big races.

Still, Shackleford got it done. In a race that most experts felt would be won by a stalker or a closer, he was able to make speed hold up. As a reference point for how tough that is, Flashpoint, who helped set the early pace with Shackleford and was still in first place after three-quarters of a mile, finished last, more than 21 lengths behind the winner.

Flashpoint and Shackleford burned out the field with an opening half-mile of 46.87 seconds, but the pace after that was nothing special. The finishing time of 1 minute, 56.47 seconds was more than three seconds off the race record set by Curlin in 2007. The Preakness was almost the opposite of the Derby, where a dawdling early pace quickened to the finish.

"Maybe this time we got them out of their game, because they had to chase us early. Sometimes a slow pace can keep closers in the race," Romans said.

If that's what happened in the Derby for Animal Kingdom, he didn't get the same trip again, or the same outcome. Not only didn't he get it three times. He didn't get it twice.

Time for horse racing to reload again. It's more than likely that neither the Derby nor the Preakness winner will even take part in the Belmont this year, which should dampen the festivities. Had Animal Kingdom won on Saturday, that scene would have been far different.

Maybe next year. Maybe some year. Maybe.

Contact columnist Bob Ford at bford@phillynews.com and read his blog at http://www.philly.com/postpatterns