With three pins in one hip and a partial replacement in the other, Denny Emerson could be forgiven for bowing out of the sport that has defined him for most of his life, and easing into one where fighting for premium couch space with his chocolate Lab, Mattie, would be his most daunting physical challenge.

But retirement is rarely an option for event riders, and Emerson, 68, is no exception. Widely regarded as a kind of “Yoda” to the eventing community, Emerson — who splits his time between farms in Stafford, Vt., and here in Southern Pines — is respected not only for his accomplishments but for his well-reasoned and authoritative arguments on issues affecting three-day eventing.

Most recently, Emerson has been front and center of a movement calling for stricter regulation within the sport. In the wake of the grim 2008 season — seven horses died during cross-country competition and U.S. Olympic rider Darren Chiacchia was gravely injured in a fall at Red Hills in Florida — eventing’s governing bodies were forced to implement more stringent safeguards concerning falls and course speed, not all of which have been well-received.

“I’ve never been a safety fanatic, but I believe in good common sense,” Emerson said over a cup of coffee one brisk morning last week. “I’m a huge proponent of riding at the appropriate level. You cannot have a sport where the price of a mistake, even a stupid mistake, is flipping and possible serious injury or death.”

Emerson, who rode on the 1974 World Championship gold medal team and twice served as the president of the United States Eventing Association (USEA), sees a link between the spate of accidents and the elimination of the long format, which comprised roads and tracks along with steeplechase and cross-country as part of the second day’s endurance phase. In 2004, in response to the International Olympic Committee’s threat to drop eventing from the Games, the “short format” was introduced, and day two became solely a cross-country test.

“When the long format went away, the test got diluted,” Emerson said. “It essentially went from a 16-mile test to a three and three-quarter miles test. Course designers decided to make up for the loss of the long format by making cross-country more technical.”

The increasing technicality of cross-country courses demands flawless pace and timing, a style of riding more often seen in show jumping.

“When you have technical questions, it has more to do with whose responsibility it is to get in the right position,” Emerson said. “These jumps come up on a horse before he has a chance to see it. The riding skill at the upper levels is very high, but the questions are too technical for most horses.”

An Olympic sport since 1912 — originally contested over five grueling days — eventing has never been an activity for the faint of heart. The late actor Christopher Reeve suffered his paralyzing injury when he went over his horse’s head after a stop on the training level course at the Culpeper Horse Trials in 1995. According to statistics provided by the USEA, a rider has an approximate 0.067 chance of falling from a horse during cross-country.

Membership in the USEA has increased by 36 percent in the past decade, with most of that demographic falling under the classification “adult amateur.” Conversely, the bulk of serious injuries to both horse and rider have occurred at the upper levels.

America’s top rider, Australian import Phillip Dutton, was involved in two rotational falls last year, one of which resulted in the death of his horse.

“What does that tell you?” Emerson said. “We’ve created a sport where our very best riders are having rotational falls.”

In the aftermath of the high-profile accidents, the United States Equestrian Federation (USEF) implemented several rules related to falls. The most controversial has been the “one fall and you’re out” rule, which mandates immediate withdrawal from competition following a horse or rider fall.

Event riders are highly competitive by nature and often take pride in retelling war stories that involve overcoming perilous situations. This quality was perhaps best illustrated by Australian rider Gillian Rolton, who fell from her horse, Peppermint Grove, during cross-country at the 2004 Olympic Games. Rolton broke her collarbone and two ribs in the first fall and remounted, only to fall again. Rolton got back on, finished the course, and the Australians won the gold medal.

That scenario would be impossible on American soil today, but Emerson firmly believes the one-fall rule could save lives.

“How many times has a rider come off the horse, got right back on, and found out later that he has a head injury?” he said. “Remember, this sport has roots in the cavalry, where it wasn’t uncommon to leave thousands of dead horses on the battlefield. Their tolerance for risk was very high.”

Emerson regularly attends the Rolex event in Lexington, Ky., held a week before the Kentucky Derby in late April. The only four-star competition in the U.S., Rolex has been the site of four cross-country horse deaths since 2007.

Emerson sees a sharp decline in the quality of riding from “say, the top 20 riders at Rolex to the bottom 20.”

“Where are the people to tell these kids they aren’t good enough?” he said. “They don’t exist. (Eventers) won’t stay with you if you tell them they can’t do it. They’ll find someone who’ll tell them they can. Every coach knows this. The honest coach will tell the truth and lose the client.”

Emerson, who has been wintering in Southern Pines since 1989, is still an active competitor, though his focus has shifted to breeding event horses. He also writes for Chronicle of the Horse magazine.

“I’ve taken two generations of homebreds to Rolex,” Emerson said. “I’ve been a careful rider, yet I’ve accomplished a lot. The worst thing I’ve ever had a horse do is bow a tendon.”

He smiled. “Of course,” he added, “some of it’s luck.”