Who deserves to be the horse of the year?

That question has stirred unusually brisk debate in the racing world because there is no clearcut choice for the title, as John Henry, Spectacular Bid and Affirmed were in the preceding three years. The choice is doubly difficult because no one has ever defined what a horse of the year should be.

Is it the horse who, on his best form, would beat everybody else at the classic distance of a mile and one quarter? Is it the horse with the greatest number of accomplishments? Because the voters can fashion their own definitions, they can make legitimate cases for Conquistador Cielo, Perrault, Lemhi Gold, Landaluce and a number of others.

The favorite to win the title is Conquistador Cielo, because his victory in the Belmont Stakes gave him the visibility and the celebrity status that the other contenders lack. And he was probably the most brilliant horse to race in America in 1982. But I refuse to vote for him because it would be a dangerous precedent to bestow the sport's highest honor on a horse with such limited achievements.

If anything, Conquistador Cielo was the horse of the week--the week of May 30. He won the Metropolitan Handicap at Belmont Park in record-breaking time, then came back five days later to capture the Belmont Stakes by 14 lengths. After those triumphs, he won a couple of more stakes against mediocre competition and then was retired before the fall championship races.

In an era when so many good horses are campaigned conservatively to avoid defeats and are whisked off to stud prematurely, the racing industry should not give its blessing to this type of management. The Eclipse Award voters should not send owners and trainers a message that they can point a horse for one or two major races, send him to stud and expect to win a championship. That is how the game is played in England, and the top horses there may race only a half dozen times in the course of a season.

America's champions ought to be in the mold of last year's horse of the year, John Henry, who raced from February to December, never ducked a challenge and still won eight out of 10 starts.

The horses who come closest to this description are Perrault and Lemhi Gold. Both had productive seasons in California during the winter and spring, and both ventured east to prove their ability further. Perrault won the Budweiser Million at Arlington Park in the summer. Lemhi Gold captured the prestigious Marlboro Cup and Jockey Club Gold Cup at Belmont.

Lemhi Gold's achievements pale under close scrutiny. He scored his two major victories at a time when most top horses were on the sidelines; the rivals he defeated were an undistinguished lot. He was basically a plodder who only once won a stakes race shorter than 1 1/2 miles. Perrault's five-length victory over him in the Budweiser Million seems a fair gauge of their relative abilities.

Perrault had a very good year. After arriving in this country from France last winter, he won the West Coast's two most important races, the Hollywood Gold Cup and the Santa Anita Handicap, although he was disqualified in the latter. After capturing the Budweiser Million, he suffered an injury during the Marlboro Cup and was retired. If he does not have the kind of record that racing historians will rhapsodize about, he is at least a solid, unobjectionable candidate to be horse of the year.

What the racing historians will remember most about 1982 is that this was the year of Landaluce. The California-based filly won all five of her races by a combined total of 46 lengths. Her victory in the Hollywood Lassie Stakes -- which she won in a record 1:08 for six furlongs -- will be remembered as one of the outstanding performances by a 2-year-old in history. Landaluce seemed destined to become an all-time great racehorse until she died last month of complications that followed a viral infection.

Purists will argue that a 2-year-old should never be the horse of the year, because he or she will not have had a chance to do the things by which we judge equine greatness: run a mile and one quarter, carry high weight, meet older rivals.

No 2-year-old could be considered for the title in a year when champions like John Henry, Spectacular Bid, Affirmed or Seattle Slew were running. But in a year where there were no great horses with a great roster of achievements, nobody deserves to have her name placed in this exalted company more than Landaluce.