Wildcat Red (4) captures the Fountain of Youth Stakes at Gulfstream Park on Saturday. (AP Photo/Gulfstream Park, Adam Coglianese) (Adam Coglianese/AP)

Some of the nation’s promising 3-year-olds raced at Gulfstream Park on Saturday and put on an exciting show. Wildcat Red won a dramatic head-and-head stretch duel to beat General a Rod in the Fountain of Youth Stakes. Constitution, who may be trainer Todd Pletcher’s best 3-year-old, ran away from a strong field in an allowance race. They all established their credentials as Kentucky Derby contenders.

Or did they?

Sometimes a high-profile race or racing card so perfectly illustrates principles of the game that they become a textbook lesson in handicapping. The events at Gulfstream make a case study into track biases — detecting their existence and judging their effect on races.

From the 1970s into the 1990s, powerful biases regularly dictated the results at certain tracks: front-runners on the rail dominated at Pimlico and Keeneland; horses swooping wide on the turn won at Belmont. But the game has changed in the past decade or two. Track superintendents are more aware of biases and learned how to eradicate them. Even so, horseplayers think they see biases everywhere.

Some believe that the Gulfstream Park strip has been speed-favoring for most of the season. I would contend that the success of speed horses is not necessarily due to a bias. While Gulfstream has an abundance of horses who fill fields for grass races, its dirt races have been underpopulated. Last Thursday, its five dirt races drew fields of seven, six, seven, seven and five. The chances of a front-runner are enhanced in a small field — there are fewer rivals to put pressure on him — and on Thursday, three of these races were won by front-runners. They paid $5, $7.60 and $3.20, all logical results that had little to do with the racing surface.

Biases are revealed by results that appear illogical: A faint-hearted runner goes to the front and pulls away from the field. Horses battle for the lead at a suicidal pace, yet they keep on going strong instead of dying in the stretch.

Gulfstream carded six races on dirt Saturday, and five of them were won by the front-runner. The exception hardly counts: Normandy Invasion, a 1-to-5 favorite against an overmatched field, would have won in any circumstances, and he had no difficulty rallying past his rivals.

In the other races before the Fountain of Youth:

●Social Inclusion, a first-time starter who had worked blazingly fast and earned rave reviews from clockers, blasted from the gate and dominated a maiden race.

●Global Strike, a Pletcher-trained maiden, was a justified 3-to-5 favorite and led all the way.

●Onlyforyou, Pletcher’s undefeated 3-year-old filly, led all the way to win the Davona Dale Stakes at the even-money favorite.

●Constitution, who had made his debut last month with a display of great speed, found himself in an allowance field devoid of front-runners. He popped from the gate and went to the lead, as his main rival, Tonalist, chased him in vain.

Four front-running winners, four logical results. If any horseplayer had told me there was a “speed bias,” I would have laughed. And then came the Fountain of Youth.

Wildcat Red had scored four previous victories, all of them in sprints. He’s the son of a sprinter, and there was ample reason to doubt that he would be effective at 11 / 16-mile stakes. General a Road is a speedster, too (albeit one with a more robust pedigree) and he also was trying to go around two turns for the first time. Accordingly, the crowd made a solid favorite of Top Billing, a proven distance runner and a strong finisher.

When the gate opened, the riders on Wildcat Red and General a Rod had the same idea: use the horse’s speed and go to the lead. They were head-and-head from the start. On the backstretch Luis Saez was putting Wildcat Red under an all-out drive and setting a breathtaking pace: three-quarters of a mile in 1 minute 10.13 seconds. General a Rod stayed glued to him. After the two colts turned into the stretch, they figured to collapse. They didn’t.

They battled to the wire, with Wildcat Red winning the photo finish. Top Billing, who had advanced to third place on the turn, barely gained on them in the stretch. Two horses with uncertain stamina engage in the most grueling of duels and neither one of them weakens? In my opinion, this would not have happened on a normal racing surface. This outcome had to be the result of a strong speed-favoring bias, and its existence prompts a reevaluation of everything that happened on the dirt at Gulfstream on Saturday.

Even though the top two finishers earned Beyer Speed Figures of 101, the best by any 3-year-olds in the nation, I would view their performances as a bias-produced aberration and would be prepared to bet against them when they run again. The track may have been an excuse for Top Billing, but — bias or no bias — he should have mustered more of a rally than he did. His was a disappointing effort.

When Constitution won his allowance race, he looked as if he might be establishing himself as the star of his generation. But with the evidence he raced over a strongly speed-favoring surface, his effort appears less impressive. He still has to prove himself in fairer conditions.

However, the horses behind Constitution deserve an upgrade. Tonalist, bounced around as he left the gate, raced four-wide around the first turn. With Constitution loose on the lead in front of him, jockey Joe Bravo had to alter the colt’s preferred stretch-running style and try to chase the leader. His second-place finish was commendable in the circumstances. So, too, was the performance of Mexicoma, who broke from the disadvantageous outside post, raced wide around both turns and rallied from last place to finish third. The 3-year-olds with the brightest futures may not be the ones who were in the winner’s circle Saturday.

For more by Andrew Beyer, visit washingtonpost.com/beyer.