The country's best 3-year-olds will be competing in stakes races from coast to coast this weekend. The results should clarify the outlook for the Kentucky Derby.

At Aqueduct, a strong field of 10 colts will contest the $362,000 Gotham Stakes. At Garden State, the Cherry Hill Mile has drawn a wide-open field of 14. Hialeah is presenting the prestigious Flamingo Stakes. And Sunday at Santa Anita, the West's best 3-year-old will run in the $500,000 Santa Anita Derby.

At least two important conclusions from these stakes are foreseeable: Snow Chief will strengthen his position as the Kentucky Derby favorite. Tasso, the champion 2-year-old of 1985 and the cofavorite in Las Vegas' future-book betting on the Derby, will be discredited after suffering a sound defeat.

*Gotham Stakes: Tasso brings a lofty reputation into this one-mile event at Aqueduct, but he gained it by beating weak opposition in slow races. Today, he faces a brilliantly fast colt named Zabaleta.

In only the third start of his career, Zabaleta won the seven-furlong Bay Shore Stakes two weeks ago in a dazzling 1:22; the other division of the stake was run in 1:23 4/5. Zabaleta probably doesn't have the pedigree or the seasoning for the Kentucky Derby, but he has the talent to rout Tasso.

*Cherry Hill Mile: Pillaster is the only colt in this large field who has won a major stake, but he was a disappointment in his 3-year-old debut. The sharpest horse in the Garden State race may be Fobby Forbes, who was impressive with a powerful finish in the Tesio Stakes at Pimlico last month.

*Flamingo Stakes: Badger Land looks like a cinch to demolish his nine nondescript rivals, but handicappers will be interested to see just how impressively he runs. His last performance, a runaway victory in the Everglades Stakes in the spectacular time of 1:46 1/5 for 1 1/8 miles, seemed almost too good to be true.

*Santa Anita Derby: Snow Chief would have been favored to win this race under any conditions, but his opposition makes him look almost unbeatable. While Snow Chief is a versatile performer who can go to the lead when he wants, all of his main rivals are confirmed stretch-runners. On the speed-favoring Santa Anita strip, horses who can take an uncontested early lead are always hard to beat.