In Maryland, no trainer is so closely associated with the quick development of 2-year-old pacers as Roger Hammer. Each year, while most trainers gingerly take to the track with their freshman pacers, Hammer pits them against tougher, older horses -- and wins.

This year is no exception.

Hammer already has won four times in 1990 with Hello Almahurst, including with a 1:56 1/5 Saturday at Rosecroft in a race in which the colt was the lone 2-year-old in a field of 3- and 4-year-olds.

Hello Almahurst and Keystone Rambler, another Hammer youngster that has beaten older horses, will be racing at Rosecroft Saturday in the $350,000 Potomac Stakes for 2-year-old pacing colts.

Also an accomplished driver with victories in 24 percent of his starts (more than 1,600 career victories), he won a division of the Potomac at Freestate Raceway in 1988, with Keystone Fabulous in a track-record 1:55 1/5.

Some have criticized Hammer's use of 2-year-olds, saying his practice of pitting them against older horses is particularly questionable.

"They {2-year-olds} have to race against them sometime," said Hammer. "{Competing} with older horses, they roll on. Next year, they come back stronger as 3-year-olds."

Hammer said races limited to rookie pacers can be troublesome, "With 2-year-olds, they break or back down the race fractions."

The development of young harness horses, and making money at it, is his forte.

Last year Hammer and partners invested $400,000 to buy nine yearlings. Individual prices ranged from $245,000 for a trotting filly to $10,000 for Hello Almahurst (Keystone Rambler brought $20,000). He races his purchases as 2- and 3-year-olds and then usually sells them. Hammer said: "I don't like to race in overnights -- those 3,000 dollar and 4,000 dollar claimers. You can't make money that way. The money is with the colts."