The field flashed past the stands for the first time during the Preakness Stakes on May 21.\r\n&ldquo;So the two speeds hook up,&rdquo; called the track announcer, as Flashpoint on the inside and Shackleford to his outside separated themselves from the other 12 contestants.\r\nThe first quarter-mile went in a sprint pace, 22.69 seconds. Animal Kingdom, the Kentucky Derby winner, had been slow into stride and was back in 13th, and when that first fractional time went up, the back of the pack seemed like the place to be. But the front-end dynamic dramatically changed over the next quarter-mile. The Preakness half-mile time was 46.87 seconds, with Shackleford basically lapped on distance-challenged Flashpoint. The pace had gone from frenetic to mild, which is why Shackleford &ndash; when Animal Kingdom made his final push &ndash; had enough energy to push pack and stay clear.\r\nShackleford is a speed horse, yes, but in the Preakness he showed mastery of the skill that separates horses running on blind instinct from horses racing with a purpose: rating.\r\nMORE&nbsp;IN&nbsp;DRF WEEKEND: Pace key to Belmont | Q&amp;A: Cot Campbell | Handicapping roundups\r\nThe origin of that word is obscure. You won&rsquo;t find it in the glossary of racing terms provided each year in the American Racing Manual. No one among a cross section of trainers and jockeys recently interviewed could illuminate the word&rsquo;s history. But most everyone at the track knows what it means. The definition &ndash; to relax and respond to a rider&rsquo;s commands during a race &ndash; often holds the key to victory. And there are few attributes more prized in American dirt racing than a speed horse who has learned to rate.\r\n&ldquo;It&rsquo;s the most dangerous thing you can have,&rdquo; said Dale Romans, Shackleford&rsquo;s trainer, &ldquo;if you have a horse that can go to the lead and relax.&rdquo;\r\nYour browser does not support iframes\r\nFew horses in the Triple Crown have proven capable of successfully leading, and Shackleford was just the eighth winner of a Triple Crown race in the last 20 years to be less than a length off the early leader. Shackleford&rsquo;s status for the Belmont Stakes had not been finalized as of May 31. But were he to line up for a rematch with Animal Kingdom at Belmont Park on June 11, he would have a chance to become the only horse since War Emblem in 2002 to be on or less than a length off the early lead in two Triple Crown race victories.\r\nShackleford already belongs to a select group of 3-year-olds who were able to win a Triple Crown race after running a lively opening quarter-mile. That is not often the case for early leaders who go on to win. Early Belmont Stakes leaders such as Touch Gold (1997), Commendable (2000), and Da&rsquo; Tara (2008) were part of dawdling pace scenarios that sapped little energy &ndash; although each of those horses displayed a willingness to rate. Touch Gold&rsquo;s victory demonstrated especially strong rating skills. Narrowly in front at the first call, Touch Gold fell behind several other horses in the middle of the race before coming back to deny Silver Charm a Triple Crown.\r\n&ldquo;Jerry Bailey was up there on Wild Rush, and he was really slowing the pace down,&rdquo; recalled Hall of Famer Chris McCarron, Touch Gold&rsquo;s rider that day. &ldquo;Touch Gold wanted to go to the lead so I let him. We turned down the backside, and Kent Desormeaux on Free House and Gary Stevens on Silver Charm could feel me slowing the pace. For a sixteenth of a mile I could feel them quicken. A lot of people think I took him back, but I really didn&rsquo;t. I just didn&rsquo;t ask him to go any faster. He tugged on me a little, but then he relaxed. He started to get some sand kicked in his face, and he relaxed even more.&rdquo;\r\nMcCarron is willing to at least hazard a guess at the origin of the term rating: He thinks it derives from the word rationing, which seems reasonable.\r\n&ldquo;The whole thing about rating is just rationing speed,&rdquo; McCarron said. &ldquo;It just means you&rsquo;re getting a horse to cooperate so that they conserve energy.&rdquo;\r\nConserving energy is not at the forefront of a horse&rsquo;s impulse to run. Nature designed the animal for speed to escape danger by flight. As all the biochemical reactions and neuronal impulses are screaming &ldquo;Run!&rdquo; here is a person on a horse&rsquo;s back saying, &ldquo;Slow down.&rdquo;\r\n&ldquo;A lot of it depends on how they were broke, if they know how to give and take,&rdquo; said jockey E.T. Baird, an Arlington-based rider who is often brilliant at rating on the lead. &ldquo;That&rsquo;s a huge plus, to be able to give and take and have another turn of foot at the end. But there are some that will never take that break. Some just want to go on.&rdquo;\r\nRandy Bradshaw knows plenty about the importance of early rating lessons. Bradshaw, a 60-year-old former racetrack trainer, breaks 60 to 85 yearlings annually at Adena Springs Farm outside Ocala, Fla. Among his trainees from the foal crop of 2008 was Animal Kingdom.\r\n&ldquo;It&rsquo;s the most important thing we do, I think,&rdquo; Bradshaw said of the rating lessons. &ldquo;That&rsquo;s the problem with all these 2-year-old sales. They learn to go so fast, when you get one, half the time you have to rebreak them. Most of these young horses don&rsquo;t have a clue.&rdquo;\r\nMost anyone can teach a horse to run fast, Bradshaw said. The trickier early lessons involve slowing everything down. At the Ocala Breeders&rsquo; Sales Company&rsquo;s April 2-year-old in training sale this spring, the fastest one-furlong work was timed in 9 seconds and change. When Bradshaw starts his youngsters off with one-furlong moves, he wants them to run at roughly half that pace.\r\n&ldquo;The first week we start to breeze an eighth of a mile in 18 seconds twice a week. The next week, 17 seconds. Next week 16 and change, then 15 and change, and we do that till we get down to 12 and change.&rdquo;\r\n&ldquo;As you go along,&rdquo; Bradshaw continued, &ldquo;once you get past the eighth, everything I do, the first eighth is always 13 or 14 and change. The worst thing you can teach a young horse is to go too fast down the backstretch &ndash; 11 and change, 12 &ndash; then come home in 15. It teaches them how to quit when they&rsquo;re tired. The way I do it, they don&rsquo;t get tired, they don&rsquo;t get disinterested. You don&rsquo;t get paid down the backside.&rdquo;\r\nThe horses who show a natural tendency toward speed also happen to be the same horses most likely to have fragile psyches. That can lead to racetrack burnouts. &ldquo;When you teach them to go too fast before they&rsquo;re ready, they can become mentally unwound,&rdquo; Bradshaw said.\r\nBradshaw said that horses, like people, learn at different points in their life. Some animals absorb little understanding of rating when they are young but somehow figure it out well into their racing career.\r\n&ldquo;Precisionist, I got the mount on him late in his 2-year-old season,&rdquo; McCarron recalled. &ldquo;He was really, really rank early in his career. It became very difficult to get him to come back to me and rate. One time, [trainer Ross Fenstermaker] said to me, &lsquo;Today, don&rsquo;t take any hold of him. Let him come out of there like he usually does, and just talk to him.&rsquo; He went a quarter in 22 4/5, three-quarters in 1:09, and a mile in 1:33, and he won by seven. Basically he rated himself. He was able to control his own energy.&rdquo;\r\nThat anecdote speaks to a misconception about rating &ndash; that a jockey induces it only by taking a strong hold of the reins. Often, a horse begins to rate under exactly the opposite conditions, when a rider eases pressure on the bit.\r\n&ldquo;Rating can be one of two things,&rdquo; said Hall of Fame rider Pat Day. &ldquo;A rider forcefully slowing the horse down, or the horse settling and getting into stride at an energy-conserving speed. To me [the latter] is rating. I&rsquo;ve ridden against riders who were very, very successful in forcefully slowing a horse down, but on the occasion when I would do that, when the running started, they&rsquo;d just collapse. They had taken so much out of themselves, they didn&rsquo;t have anything left. I tried to use a minimal amount of encouragement. Sometimes taking a hold is self-defeating. Just because they&rsquo;ve gone a half in 48 seconds, that doesn&rsquo;t mean they have something to finish with. I&rsquo;d rather have a horse go in 46 and change and be doing it comfortably.&rdquo;\r\nDay was aboard Louis Quatorze when he wired the Preakness in 1996 just two weeks after the horse had shown little in the Derby. &ldquo;Nick had no plausible excuse for his performance,&rdquo; Day said, referring to trainer Nick Zito. &ldquo;Before the Preakness, he said, &lsquo;Pat, just kick him away from there, put him on the lead, and see how it goes.&rsquo; As soon as he cleared, I dropped my hands back on him, he got comfortable, and when Skip Away came to him, he just bounded away.&rdquo;\r\nThat sounds something like McCarron describing his front-running ride on Go for Gin in the 1994 Derby. &ldquo;When I was laying second going past the stands the first time, Go for Gin was pulling hard on me,&rdquo; McCarron said. &ldquo;I let him out a notch, and as soon as he got out in front, I could feel him completely relax. He came right back, and all the way down the backside I had just a very light hold on him. I saved all my energy, he saved all of his.&rdquo;\r\nIndeed, the key to speed horses rating on the lead in routes often lies in making a clear lead, or at least racing in the clear on the outside, like Shackleford in the Preakness. War Emblem bossed the 2002 Derby and Preakness while showing the way out front, but when he got away slowly in the Belmont, all was lost.\r\n&ldquo;The only trouble I ever had with him was when I tried to take him back,&rdquo; said Bobby Springer, who trained War Emblem until about two weeks before the Kentucky Derby, when he was sold and turned over to Bob Baffert. &ldquo;Once he made the lead, everything slowed down for him.&rdquo;\r\nSpringer said he often has encouraged his trainees to race from the front, where, like Shackleford over paceless Animal Kingdom in the Preakness, the leader has an inherent edge.\r\n&ldquo;You take a smart horse, an athlete that can run long, and they can do a lot on the front end. You get a horse relaxing on the lead, their blood pressure goes down,&rdquo; Springer said.\r\nYour browser does not support iframes\r\nThe only time Shackleford wasn&rsquo;t on the lead or pushing the pace in a route race, in the Fountain of Youth Stakes last winter, he stopped at the top of the stretch and lost by 23 lengths. In his next race, the Florida Derby, he made all the running, going fast on the front end before Dialed In nailed him on the wire. In the Kentucky Derby, Shackleford had the lead at the stretch call but not enough energy left to hold off three rallying rivals. There was rating going on in those races, but Shackleford was still working out the kinks.\r\n&ldquo;He&rsquo;s improved every race,&rdquo; Romans said. &ldquo;In the Derby, he looked around. He got the lead, and he got to joking, and he did the same thing in the Florida Derby. Now he&rsquo;s starting to figure it out. Having that horse alongside him last time really helped. It made him get big.&rdquo;\r\nJockey Jesus Castanon, winning his first Classic race, had an aggressive animal beneath going into the first turn of the Preakness. Shackleford wanted a piece of Flashpoint, which is why the first quarter-mile was so fast.\r\n&ldquo;In the first turn I was just trying not to get too close to the other horse,&rdquo; Castanon said. &ldquo;Finally, he was able to come back to me and relax.&rdquo;\r\nThe pace slowed. Shackleford had started rating. And that was the race.