On Sunday Red Pony Farm founder and owner Karin Magid made her bid for the Century Club at the Martha’s Vineyard Horse Council’s dressage show. Founded in 1996 by the Dressage Foundation, the club recognizes riders and horses whose combined age totals 100 years or more.

Ms. Magid is 74 and her horse Pip turned 26 on June 3. This was the first moment that 100 combined years was possible and she was not taking any chances.

“We began preparing in November, but so many things can go wrong,” she said. “The horse can get sick, hurt. And it is not just the horse, I’m old too.”

Ms. Magid was about five years old when she got on her first horse. “I lived down the road from an Arab horse farm and I was hooked from the first time I got on a horse. I first rode at Gordon Wright’s barn in Westchester. I was a prodigal rider, but at 18 I traded in my love of horses for boys,” she said.

After graduating from Sarah Lawrence College, she moved to England and pursued a career in filmmaking. She also kept riding, buying her first horse when she was 38. In 1995, she bought and built Red Pony Farm or in her words, “mortgaged myself for life.”

On Sunday, the Agricultural Fair grounds were sunny, hot and dusty. Ms. Magid arrived early to settle Pip who was vibrating, dancing and prancing around with her goddaughter, Katrina Heilbroner, who was riding him.

“He feels great,” said Ms. Heilbroner, who has been riding Pip since she was five and now rides at Brown University.

Older riders at the horse show admitted that a Century Club ride was certainly on their bucket list. West Tisbury resident Julie Skinner had just completed hers with her horse Graphite last year. Spectator and rider Suzanne Modigliani echoed Ms. Magid’s thoughts. “It is a very unusual and special thing when the numbers, the horse and rider, all line up,” she said.

When Ms. Magid’s turn came the music started and she and Pip did a side prance into the ring before the judge was ready.

“Can you wait for the bell?” judge Crystal Taylor called out.

“No,” Ms. Magid yelled back to much laughter.

During the ride other trainers and riders whispered phrases, such as balanced seat, serpentine canter and flying change. The movements in the ring evoked a feeling reminiscent of a couple taking to the dance floor to celebrate their 50th wedding anniversary.

When Ms. Magid and Pip finished, there was a huge cheer from the crowd, with fans and friends congratulating the two of them.

“Don’t call this my swan song,” Ms. Magid said. “I am hooked.”