Picking the winner of this year's Belmont Stakes is not easy. Horses such as last year's winner, Conquistador Cielo, do not come along often.

However, Deputed Testamony, a colt beautifully developed by his trainer, Bill Boniface, appears to be the best bet to take home the champion's share of the $358,500 purse.

The son of Traffic Cop has Donald Miller in the irons and that is a plus. Miller, who will turn 20 on Belmont day, has a remarkable ability to keep horses clear in traffic and the Belmont's big field makes a clever rider extremely valuable.

Of the race's entrants, only Slew O'Gold, a colt who drew the favorable inside post position, appears capable of running a race that could be termed "brilliant."

The son of Seattle Slew blew away some good colts in the Peter Pan Stakes at Belmont strip in his last race, completing the 1 1/16th miles in 1:46 4/5 and winning that race by 12 lengths. Moreover, he has the talented Angel Cordero as his jockey.

Caveat, my choice to win last month's Kentucky Derby, has hit his peak at the right time. Observers claim that he should have won the Derby and that his races since and his energetic workouts make him formidable. His trainer, Woody Stpehens, seems to underrate him, but he will be heavily backed by the New York public, as will Slew O'Gold. Caveat has Laffit Pincay as his jockey and I think he'll finish second.

Of the others, Dixieland Band, a colt who had blinkers added to his equipment in his best race this year, has a longshot chance with the incomparable Bill Passmore in the saddle. But this well-bred colt has some leg problems, and the 1 1/2 miles of the Belmont may be beyond him right now.

The race should show Slew O'Gold and Au Point in front early. The last quarter mile, when the real racing will begin, Deputed Testamony, Caveat and Dixeland Band--all, coincidentally, Maryland-breds--should finish one-two-three, with the winner hitting the wire in 2:28 1/5.