Racing luck. It’s an oft-repeated expression on the racetrack, interchangeably applied to a win or a loss. Super Saver had good racing luck last weekend, thanks in no small part to a post position (4) that kept him out of trouble in the early stages of the race. It didn’t hurt that his jockey, Louisiana native Calvin Borel, had already won two of the last three Kentucky Derbies and knew the Churchill Downs racing strip as well as he knew his mawmaw’s jambalaya recipe.

But for my money, the luckiest horse of all Kentucky Derby contenders past and present is a 20-year-old gelding with arthritis, a shaggy mane and gums that look like half-eaten corncobs.

His registered name is Truth of It All, and as a close, personal friend, I am allowed to call him “Dennis,” his childhood nickname. Dennis owes me money; if he could talk, he’d probably wind up convincing me all those losing bets were “emotional investments” that yielded long-term benefits. He’d be right.

In his heyday, Truth of It All was the 1992 champion 2-year-old in Canada and a legitimate contender for the 1993 Kentucky Derby. Truth of It All ran against the top 3-year-olds of that year in such races as the Rebel Stakes, the Lexington and the Ohio Derby.

He finished 10th in the Kentucky Derby, and it was all downhill from there. A few lackluster stakes performances earned him a one-way ticket to the claiming ranks, where horses can toil for years until age or injury catches up to them.

Still, I have to admit, I was shocked to pick up a Daily Racing Form on Sept. 14, 1997, and see Truth of It All’s name listed in the entries for a $2,000 claiming race at Los Alamitos, a lower-level racetrack about 20 miles southeast of Los Angeles. Despite its proximity to first-class racing at Hollywood Park and Santa Anita, Los Alamitos is light years away in terms of quality bloodstock. Often the last stop for a horse before breaking down or being sent to slaughter, Los Alamitos runs 4 1/2-furlong races for thoroughbreds (just under half the distance of the 1 1/4-mile Kentucky Derby) as well as Arabian, Appaloosa and quarter horse races.

Scanning his past performance chart, I noted that Truth of It All hadn’t raced in a year, and that he was now being trained by John Cooper, a quarter horse trainer. I’d met Cooper once before in the course of researching a feature on the champion quarter horse Refrigerator for my newspaper, the Riverside Press-Enterprise. I called Cooper and asked about Truth Of it All’s fitness for racing.

“Well,” Cooper began, “I think he’ll make it around, but I don’t know how many races he has left. His ankles are just about fused, and I can’t work him too hard. Frankly, I hope the owner comes to his senses and does the right thing for the horse.”

The right thing for the horse. I guess an argument can be made that the right thing for any horse is to keep him or her as far as possible from any racetrack. This is something that I, an ardent but conflicted racing fan with several retired thoroughbreds of my own, struggle with constantly.

As a racing writer for more than 20 years, I have been lucky to witness some of the sport’s greatest moments — Sunday Silence and Easy Goer’s epic stretch duel in the 1989 Preakness, Cigar’s 16th straight victory, Zenyatta’s pre-race antics followed by any of her jaw-dropping wins. Along with those highlights came heartbreaking lows I wish I hadn’t seen — Go for Wand trying to run on a mangled leg in the 1990 Breeders’ Cup Distaff, Kentucky Derby winner Barbaro pulling up with a broken hind leg just seconds after leaving the gate in the 2006 Preakness, the filly Eight Belles’ collapsing under two broken front legs after finishing second in the 2008 Kentucky Derby.

Now, I was faced with a situation that seemed to be a bad step away from disaster. I called Truth of It All’s breeder, Hurstland Farm proprietor Alfred Nuckols Jr., and told him of the horse’s plight. Nuckols, whose family has been a force in the thoroughbred industry since the 1890s, had followed Truth Of it All’s career but lost track of him.

“I don’t want to see him running anymore,” Nuckols said, emotion creeping into his voice. “Please tell the trainer I’d like to bring him back home.”

Cooper tried to persuade the owners to sell the horse before the race. They declined the offer, and Truth of It All went to the post as the 5-1 fourth betting choice.

He finished ninth of 10 horses and pulled up lame. I waited until I was sure the horse could walk back to the barn. Then, I looked for Cooper.

I didn’t have to look far. Cooper was standing behind me, talking on his cell phone. He finished the call and said, “How’d you like to buy a horse for $1?” We shook hands, and 48 hours later, Truth of It All was on a plane bound for Blue Grass Airport in Lexington, Ky.

I traveled with the horse and will never forget the sight of Nuckols waiting for us on the tarmac with a two-horse trailer. Nuckols led the horse down the ramp and guided him into the trailer, and just like that, Truth of It All became Dennis again.

I made my annual pilgrimage to Hurstland Farm two weeks ago. Dennis seemed happy to see me, but his eyes were locked on the distinctive bag of Starlight Peppermints I brought in tribute. A voracious cribber, Dennis has worn his front teeth down to nubs from chewing on the fenceposts. Nuckols never complains about having to replace the boards Dennis destroys; watching Nuckols with the horse, I suspect Dennis could torch the family home and still get his daily dose of peppermints.

Do I take credit for helping Dennis return to his birthplace to live out his days with two other retired geldings and a pensioned broodmare on 375 acres of equine nirvana? You bet I do. Thanks to Dennis, I can say I’ve truly been a part of the Kentucky Derby experience.

And I get to win it every year.