In last Sunday's first race at Aqueduct, nine out of the ten horses listed in the program were described as either brown or dark bay or brown, with a solitary chestnut bringing slight diversity to the field. None of the horses had any distinctive white marks.

"All these horses come in plain brown wrappers," said New York Racing Association Chief Horse Identifier Janet Reid as she made her final check in the paddock.

To the uninitiated, it could be almost impossible to tell these horses apart, but similar packaging doesn't fool Reid. Making sure that the correct horses are running in the correct races is a full-time job for NYRA's horse identification office.

NYRA has one of the most thorough horse identification procedures of any racing jurisdiction. Chief identifier Reid works with a team of four others - identifiers Carol Dolan and Anthony Jaccino, photographer Diane Connor, and clerk Karen Brady - to ensure that every horse running is exactly who the connections claim it to be.

"The other jurisdictions don't do nearly as much as we do," Reid said. "Most have just one horse identifier and one assistant and the tattoo is usually the final word."

Not in New York. Reid and her team don't "flip lips" to check a horse's tattoo unless they absolutely have to, preferring instead to rely on an exhaustive assessment of a horse's various markings backed up by multiple photographs.

"A tattoo is a man-made marking and men can make mistakes," Reid explained.

Nature, however, doesn't lie. All horses have irregular growths on the inside of each leg that do not change in size or shape over the lifetime of the adult horse and, like human fingerprints, are unique. These “chestnuts”, also known as "night-eyes" are a critical part of the identification process, particularly when Reid makes her final check in the paddock and racing equipment can obscures her view of the white markings and differences in the hair pattern called "cowlicks" that also help.

To ensure that the pre-race checks run smoothly, the horse identifiers try to work 2-3 weeks in advance assembling the information they need to confirm that horses match up with their information. The team spends mornings in the barns with copies of each horse's foal certificate from the Jockey Club comparing markings and taking digital photographs for the office's database.

During busy times in the spring and summer, the team identifies as many as 30 horses each morning, but never fewer than 10. With 254 race days on the calendar for 2009, Reid and her team are looking at more than 2,500 identifications this year alone.

Three body shots and close-ups of all four night-eyes are filed in the office's online database and in hard copy, along with copies of the foal certificates and each horse's current Coggins test results. Each race day, the relevant information for each horse running is compiled into binders by race that Reid uses for her paddock assessments, which she does in stages. Her first examination comes while the horses are being saddled, and she checks once more as they walk out to the track.

Complicated as the horse identifier's job may seem, Reid knows these checks and cross-checks are essential.

“We’re maintaining the integrity of racing and protecting the public,” Reid said.