The phone rings at Hilltop Farm and breeding manager Natalie DiBerardinis answers. Just as she suspected, it is a mare owner looking for advice. Which stallion would be a good match for her mare, the caller asks anxiously. With scientific advances in artificial insemination, the choices for a perfect partner have never been greater, but that doesn't mean the selection process is any simpler. DiBerardinis asks the owner a few questions about her mare and suggests she complete Hilltop's online questionnaire. After reading it, she and the caller will talk again to discuss the options.

Kristi Nunnink's default expression is a smile. It doesn't matter how hard she's working, what level she's riding or how the horse under her is performing -- her mouth curls faintly upward, unforced. It may just be a coincidence of facial structure, or it may be a product of years of habit. But either way, the expression fits her, because Nunnink may very well be the happiest rider at Rolex Kentucky. At 48, she's heading to her first CCI**** with her horse of a lifetime.